I want to report that i also have the same problem:
http://ubuntuone.com/4QKmKzyZ1r5OsMVKvqndl4
http://ubuntuone.com/2emstn5Aq0qvNy1alTqHcJ

The problem occurs on my laptop and I also have a desktop on which i do not have this problem.
Both pcs are running under ubuntu 11.10 64bits.

here are some outputs:

############################################
On the laptop with the problem:

$ ubuntu-tweak -d
[app][DEBUG] Distribution: Ubuntu 11.10 oneiric
Application: Ubuntu Tweak 0.6.0-1~oneiric1
Desktop:ubuntu (main.py:259)
[app][DEBUG] Load modules, remove: False (main.py:191)
[ModuleLoader][INFO] Loading system modules for tweaks... (__init__.py:53)
[ModuleLoader][DEBUG] Try to load module: metacity (__init__.py:149)

(ubuntu-tweak:24366): GConf-WARNING **: : You can't use a GConfEngine that has an active GConfClient wrapper object. Use GConfClient API instead.

(ubuntu-tweak:24366): GConf-WARNING **: : You can't use a GConfEngine that has an active GConfClient wrapper object. Use GConfClient API instead.
Checking if settings need to be migrated ...no
Checking if internal files need to be migrated ...no
Backend     : gconf
Integration : true
Profile     : unity
Adding plugins
Skipping upgrade com.canonical.unity.unity.01.upgrade
Skipping upgrade com.canonical.unity.unity.02.upgrade
Initializing core options...done
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: icons (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: loginsettings (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: ccm (__init__.py:149)
[ModuleLoader][DEBUG] Try to load module: lockdown (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: fonts (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: compiz (__init__.py:149)

(ubuntu-tweak:24366): GConf-WARNING **: : You can't use a GConfEngine that has an active GConfClient wrapper object. Use GConfClient API instead.

(ubuntu-tweak:24366): GConf-WARNING **: : You can't use a GConfEngine that has an active GConfClient wrapper object. Use GConfClient API instead.
Checking if settings need to be migrated ...no
Checking if internal files need to be migrated ...no
Backend     : gconf
Integration : true
Profile     : unity
Adding plugins
Skipping upgrade com.canonical.unity.unity.01.upgrade
Skipping upgrade com.canonical.unity.unity.02.upgrade
Initializing core options...done
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: misc (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: theme (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: session (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: workarounds (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: nautilus (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: unity (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][INFO] Loading user extensions for tweaks... (__init__.py:63)
[app][INFO] Creating ModuleButton: <class 'fonts.Fonts'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'misc.Misc'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'theme.Theme'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'loginsettings.LoginSettings'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'session.Session'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'compiz.Compiz'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'icons.Icon'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'unity.UnitySettings'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'metacity.Metacity'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'nautilus.Nautilus'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'lockdown.LockDown'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'workarounds.Workarounds'> (main.py:68)
[app][DEBUG] Load modules, remove: False (main.py:191)
[ModuleLoader][INFO] Loading system modules for admins... (__init__.py:53)
[ModuleLoader][DEBUG] Try to load module: scripts (__init__.py:149)
[ModuleLoader][DEBUG] Try to load module: userdir (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: desktoprecovery (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: sourcecenter (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: filetypemanager (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: sourceeditor (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: templates (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: shortcuts (__init__.py:149)

(ubuntu-tweak:24366): GConf-WARNING **: : You can't use a GConfEngine that has an active GConfClient wrapper object. Use GConfClient API instead.

(ubuntu-tweak:24366): GConf-WARNING **: : You can't use a GConfEngine that has an active GConfClient wrapper object. Use GConfClient API instead.
Checking if settings need to be migrated ...no
Checking if internal files need to be migrated ...no
Backend     : gconf
Integration : true
Profile     : unity
Adding plugins
Skipping upgrade com.canonical.unity.unity.01.upgrade
Skipping upgrade com.canonical.unity.unity.02.upgrade
Initializing core options...done
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: appcenter (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][INFO] Loading user extensions for admins... (__init__.py:63)
[app][INFO] Creating ModuleButton: <class 'desktoprecovery.DesktopRecovery'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'userdir.UserDir'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'shortcuts.Shortcuts'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'filetypemanager.FileTypeManager'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'sourceeditor.SourceEditor'> (main.py:68)
[ClipPage][DEBUG] Load clips, do_remove: False (__init__.py:143)
[ModuleLoader][INFO] Loading system modules for clips... (__init__.py:53)
[ModuleLoader][DEBUG] Try to load module: cleanerinfo (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: hardwareinfo (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: userinfo (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: systeminfo (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: updateinfo (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][INFO] Loading user extensions for clips... (__init__.py:63)
[ClipPage][DEBUG] Load clip: HardwareInfo (__init__.py:164)
[ClipPage][DEBUG] Load clip: SystemInfo (__init__.py:164)
[ClipPage][DEBUG] Load clip: CleanerInfo (__init__.py:164)
[ClipPage][DEBUG] Load clip: UpdateInfo (__init__.py:164)
[ClipPage][DEBUG] Load clip: UserInfo (__init__.py:164)
[ClipPage][DEBUG] Overview page: setup_rencently_used (__init__.py:256)
[ModuleLoader][INFO] Loading module "Nautilus" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "LoginSettings" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "Theme" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "Compiz" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "LockDown" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "Session" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "Icon" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "UnitySettings" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "Metacity" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "DesktopRecovery" for "admins"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "SourceEditor" for "admins"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "Misc" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "Workarounds" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "FileTypeManager" for "admins"... (__init__.py:107)
[ClipPage][DEBUG] slide_clips (__init__.py:176)
[ClipPage][DEBUG] slide_clips (__init__.py:176)
[GSetting][DEBUG] The the value for type: None and value: (1176, 685) (gsettings.py:41)

############################################
on my desktop with no problem:
$ ubuntu-tweak -d
[app][DEBUG] Distribution: Ubuntu 11.10 oneiric
Application: Ubuntu Tweak 0.6.0-1~oneiric1
Desktop:None (main.py:259)
[app][DEBUG] Load modules, remove: False (main.py:191)
[ModuleLoader][INFO] Loading system modules for tweaks... (__init__.py:53)
[ModuleLoader][DEBUG] Try to load module: misc (__init__.py:149)

Checking if settings need to be migrated ...no
Checking if internal files need to be migrated ...no
Backend     : ini
Integration : true
Profile     : default
Adding plugins
Skipping upgrade com.canonical.unity.unity.01.upgrade
Skipping upgrade com.canonical.unity.unity.02.upgrade
Initializing core options...done
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: ccm (__init__.py:149)
[ModuleLoader][DEBUG] Try to load module: workarounds (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: nautilus (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: metacity (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: theme (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: fonts (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: lockdown (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: unity (__init__.py:149)
[ModuleLoader][DEBUG] Try to load module: compiz (__init__.py:149)

Checking if settings need to be migrated ...no
Checking if internal files need to be migrated ...no
Backend     : ini
Integration : true
Profile     : default
Adding plugins
Skipping upgrade com.canonical.unity.unity.01.upgrade
Skipping upgrade com.canonical.unity.unity.02.upgrade
Initializing core options...done
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: loginsettings (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: session (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: icons (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][INFO] Loading user extensions for tweaks... (__init__.py:63)
[app][INFO] Creating ModuleButton: <class 'fonts.Fonts'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'misc.Misc'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'theme.Theme'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'loginsettings.LoginSettings'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'session.Session'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'compiz.Compiz'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'icons.Icon'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'metacity.Metacity'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'nautilus.Nautilus'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'lockdown.LockDown'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'workarounds.Workarounds'> (main.py:68)
[app][DEBUG] Load modules, remove: False (main.py:191)
[ModuleLoader][INFO] Loading system modules for admins... (__init__.py:53)
[ModuleLoader][DEBUG] Try to load module: desktoprecovery (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: scripts (__init__.py:149)
[ModuleLoader][DEBUG] Try to load module: userdir (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: shortcuts (__init__.py:149)

Checking if settings need to be migrated ...no
Checking if internal files need to be migrated ...no
Backend     : ini
Integration : true
Profile     : default
Adding plugins
Skipping upgrade com.canonical.unity.unity.01.upgrade
Skipping upgrade com.canonical.unity.unity.02.upgrade
Initializing core options...done
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: templates (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: sourceeditor (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: appcenter (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: filetypemanager (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: sourcecenter (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][INFO] Loading user extensions for admins... (__init__.py:63)
[app][INFO] Creating ModuleButton: <class 'desktoprecovery.DesktopRecovery'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'userdir.UserDir'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'shortcuts.Shortcuts'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'filetypemanager.FileTypeManager'> (main.py:68)
[app][INFO] Creating ModuleButton: <class 'sourceeditor.SourceEditor'> (main.py:68)
[ClipPage][DEBUG] Load clips, do_remove: False (__init__.py:143)
[ModuleLoader][INFO] Loading system modules for clips... (__init__.py:53)
[ModuleLoader][DEBUG] Try to load module: hardwareinfo (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: systeminfo (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: updateinfo (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: cleanerinfo (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][DEBUG] Try to load module: userinfo (__init__.py:149)
[ModuleLoader][DEBUG] is_supported_distro (__init__.py:212)
[ModuleLoader][INFO] Loading user extensions for clips... (__init__.py:63)
[ClipPage][DEBUG] Load clip: HardwareInfo (__init__.py:164)
[ClipPage][DEBUG] Load clip: SystemInfo (__init__.py:164)
[ClipPage][DEBUG] Load clip: CleanerInfo (__init__.py:164)
[ClipPage][DEBUG] Load clip: UpdateInfo (__init__.py:164)
[ClipPage][DEBUG] Overview page: setup_rencently_used (__init__.py:256)
[ModuleLoader][INFO] Loading module "LoginSettings" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "Theme" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "Misc" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "Fonts" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "UnitySettings" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "SourceEditor" for "admins"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "Metacity" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "Icon" for "tweaks"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "DesktopRecovery" for "admins"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "UserDir" for "admins"... (__init__.py:107)
[ModuleLoader][INFO] Loading module "FileTypeManager" for "admins"... (__init__.py:107)
[ClipPage][DEBUG] slide_clips (__init__.py:176)
[ClipPage][DEBUG] slide_clips (__init__.py:176)
[ClipPage][DEBUG] slide_clips (__init__.py:176)
[app][DEBUG] on_overview_button_toggled and widget.active is: False (main.py:522)
[app][DEBUG] on_tweaks_button_toggled and widget.active is: True (main.py:522)
[app][DEBUG] on_tweaks_button_toggled and widget.active is: True (main.py:522)
[GSetting][DEBUG] The the value for type: None and value: (1107, 866) (gsettings.py:41)