Ditto on this bug for me.  

     richw@watson:~$  shutter --version  
        0.90 Rev.1252

I have some NFS mounts -- however, when I set shutter to use the default ( ~ ) -- which is not mounted via NFS, I still get the error.

I also noticed that there are a few packages that probably should be added as dependencies for shutter as well:

    libimage-exiftool-perl
    libnet-dbus-glib-perl 

These will twart the warnings for the following:

    WARNING: Net::DBus::GLib is missing --> Ubuntu One support will be disabled!
    WARNING: Image::ExifTool is missing --> writing Exif information will be disabled!

##MY ENVIRO
- Release: Ubuntu 12.04 (precise)
- GNOME: unknown (unknown)
- Xfce: 4.8
  - Note:  I use Xubuntu
- Kernel: 3.2.0-36-generic (#57-Ubuntu SMP Tue Jan 8 21:44:52 UTC 2013)

## STARTING SHUTTER FROM COMMAND LINE
    richw@watson:~$ rm -rf .shutter/
    richw@watson:~$ shutter

        ERROR: settingsfile /home/richw/.shutter/settings.xml does not exist

        INFO: new plugin information detected - /usr/share/shutter/resources/system/plugins/perl/spbardistortion/spbardistortion
        ... blah blah info plugin...
        INFO: new upload-plugin information detected - /usr/share/shutter/resources/system/upload_plugins/upload/TwitPic

        (shutter:17724): gnome-vfs-modules-WARNING **: Could not initialize inotify

USER ACTION: take a screenshot

<Error message 'Error while adding the file monitor. Unsupported operation' pops up>
USER ACTION: click cancel

<Image appears in the main window>
USER ACTION:  click the 'x' to close the image tab in the main window

        *** unhandled exception in callback:
        ***   Can't call method "cancel" on an undefined value at /usr/bin/shutter line 5655, <DATA> line 19.
        ***  ignoring at /usr/bin/shutter line 2893, <DATA> line 19.


## STARTING SHUTTER FROM COMMAND LINE WITH DEBUG
    richw@watson:~$ rm -rf .shutter/
    richw@watson:~$ shutter --debug

        INFO: gathering system information...
        Linux watson 3.2.0-36-generic #57-Ubuntu SMP Tue Jan 8 21:44:52 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
        Ubuntu 12.04.1 LTS \n \l

        Glib 1.241 
        Gtk2 1.223 
        Glib built for 2.30.1, running with 2.32.3
        Gtk2 built for 2.24.6, running with 2.24.10

        ERROR: settingsfile /home/richw/.shutter/settings.xml does not exist

        INFO: new plugin information detected - /usr/share/shutter/resources/system/plugins/perl/spbardistortion/spbardistortion
        Barrel Distortion - /usr/share/shutter/resources/system/plugins/perl/spbardistortion/spbardistortion
         ... blah blah info plugin...

        Current window manager: Xfwm4
        Current window manager: Xfwm4

        type_changed was emitted by widget Gtk2::ComboBox=HASH(0xaf8b58)
        qvalue_changed was emitted by widget Gtk2::HScale=HASH(0x3530508)

        (shutter:21906): gnome-vfs-modules-WARNING **: Could not initialize inotify
        
        progname_toggled was emitted by widget Gtk2::CheckButton=HASH(0xae27e0)
        im_colors_changed was emitted by widget Gtk2::ComboBox=HASH(0xae27b0)
        im_colors_toggled was emitted by widget Gtk2::CheckButton=HASH(0x3483650)
        thumbnail_changed was emitted by widget Gtk2::HScale=HASH(0x34836f8)
        thumbnail_toggled was emitted by widget Gtk2::CheckButton=HASH(0x3483740)
        bordereffect_toggled was emitted by widget Gtk2::CheckButton=HASH(0x34837b8)
        bordereffect_changed was emitted by widget Gtk2::SpinButton=HASH(0x3483800)
        menu_delay_changed was emitted by widget Gtk2::SpinButton=HASH(0x3483ae8)
        hide_time_changed was emitted by widget Gtk2::SpinButton=HASH(0x34842e0)
        ns_changed was emitted by widget Gtk2::ComboBox=HASH(0x3484310)
        fct_update_tray_menu was called by Gnome2::Wnck::Screen=HASH(0x3049e18)

USER ACTION: take a screenshot

        full was emitted by widget Gtk2::MenuToolButton=HASH(0x34751b0)
        3 Ns used in wild-card
        Searching for files with pattern: (?^u:\$name_(\d\d\d)\.png)
        Searching for files with pattern: (?^u:.{1,}_(\d\d\d)\.png)
        Comparing .dmrc
        Comparing foo.pdf
        Comparing A_003.png
        003 is currently greatest value...
        Comparing .gtkrc-2.0
        Comparing .goutputstream-XGYBQW
        Comparing .xscreensaver.swp
        Comparing .recently-used
        ...
    >>> compares every bloody file in my home directory -- whether it's a PNG file or not <<<< 
       ...
        Comparing Selection_006.png
        006 is currently greatest value...
        Comparing qlgt.db
        Comparing .gorillarc
        Comparing .goutputstream-X6AAQW
        Comparing .bashrc
        Parsing wildcards for /home/richw/$name_007.png
        Parsed $width and $height: /home/richw/$name_007.png
        Parsed $profile: /home/richw/$name_007.png
        Parsed $name: /home/richw/A_007.png
        New uri after exists check: file:///home/richw/A_007.png
        Trying to save file to /home/richw/A_007.png
        Saving file /home/richw/A_007.png, png, 9
        Updating fileinfos for key: [2] - A_007.png
        file:///home/richw/A_007.png thumbnail created
        file:///home/richw/A_007.png thumbnail already exists


<Error message Error while adding the file monitor. Unsupported operation pops up>
USER ACTION: click cancel

        fct_update_tray_menu was called by Gnome2::Wnck::Screen=HASH(0x3049e18)
        screenshot successfully saved to /home/richw/A_007.png!
        fct_update_tray_menu was called by Gnome2::Wnck::Screen=HASH(0x3049e18)

<Image appears in the main window>
USER ACTION: click the 'x' to close the image tab in the main window

        fct_update_tray_menu was called by Gnome2::Wnck::Screen=HASH(0x3049e18)
        *** unhandled exception in callback:
        ***   Can't call method "cancel" on an undefined value at /usr/bin/shutter line 5655, <DATA> line 19.
        ***  ignoring at /usr/bin/shutter line 2893, <DATA> line 19.

USER ACTION: quit shutter from Systray > Quit 

        fct_update_tray_menu was called by Gnome2::Wnck::Screen=HASH(0x3049e18)
        quit was emitted by widget Gtk2::ImageMenuItem=HASH(0x30652c0)



## WORKAROUND: Start shutter with the '--no_session' flag

    richw@watson:~$ rm -rf .shutter/
    richw@watson:~$ shutter --debug  --no_session 


        INFO: gathering system information...
        Linux watson 3.2.0-36-generic #57-Ubuntu SMP Tue Jan 8 21:44:52 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
        Ubuntu 12.04.1 LTS \n \l

        Glib 1.241 
        Gtk2 1.223 
        Glib built for 2.30.1, running with 2.32.3
        Gtk2 built for 2.24.6, running with 2.24.10

        ERROR: settingsfile /home/richw/.shutter/settings.xml does not exist

        INFO: new plugin information detected - /usr/share/shutter/resources/system/plugins/perl/spbardistortion/spbardistortion
        Barrel Distortion - /usr/share/shutter/resources/system/plugins/perl/spbardistortion/spbardistortion
         ... blah blah info plugin...

        Current window manager: Xfwm4
        Current window manager: Xfwm4

        type_changed was emitted by widget Gtk2::ComboBox=HASH(0xaf8b58)
        qvalue_changed was emitted by widget Gtk2::HScale=HASH(0x3530508)

        (shutter:21906): gnome-vfs-modules-WARNING **: Could not initialize inotify
        
        progname_toggled was emitted by widget Gtk2::CheckButton=HASH(0xae27e0)
        im_colors_changed was emitted by widget Gtk2::ComboBox=HASH(0xae27b0)
        im_colors_toggled was emitted by widget Gtk2::CheckButton=HASH(0x3483650)
        thumbnail_changed was emitted by widget Gtk2::HScale=HASH(0x34836f8)
        thumbnail_toggled was emitted by widget Gtk2::CheckButton=HASH(0x3483740)
        bordereffect_toggled was emitted by widget Gtk2::CheckButton=HASH(0x34837b8)
        bordereffect_changed was emitted by widget Gtk2::SpinButton=HASH(0x3483800)
        menu_delay_changed was emitted by widget Gtk2::SpinButton=HASH(0x3483ae8)
        hide_time_changed was emitted by widget Gtk2::SpinButton=HASH(0x34842e0)
        ns_changed was emitted by widget Gtk2::ComboBox=HASH(0x3484310)
        fct_update_tray_menu was called by Gnome2::Wnck::Screen=HASH(0x3049e18)

USER ACTION: Edit > Preferences > Set directory and filename ( /data/screenshots/%Y-%m-%d--%H-%M-%S__$nb_name__%NN.png )

        fct_update_tray_menu was called by Gnome2::Wnck::Screen=HASH(0x4040d10)
        Gtk-WARNING **: Unable to find default local directory monitor type at /usr/bin/shutter line 3888, <DATA> line 19.
        Gtk-WARNING **: Unable to find default local directory monitor type at /usr/bin/shutter line 3888, <DATA> line 19.
        Gtk-WARNING **: Unable to find default local directory monitor type at /usr/bin/shutter line 3888, <DATA> line 19.
        Gtk-WARNING **: Unable to find default local directory monitor type at /usr/bin/shutter line 3888, <DATA> line 19.
        Gtk-WARNING **: Unable to find default local directory monitor type at /usr/bin/shutter line 3888, <DATA> line 19.
        Gtk-WARNING **: Unable to find default local directory monitor type at /usr/bin/shutter line 3888, <DATA> line 19.
        Gtk-WARNING **: Unable to find default local directory monitor type at /usr/bin/shutter line 3888, <DATA> line 19.
        fct_update_tray_menu was called by Gnome2::Wnck::Screen=HASH(0x4040d10)
        Gtk-WARNING **: Unable to find default local directory monitor type at /usr/bin/shutter line 3888, <DATA> line 19.

USER ACTION: take a screenshot

        fct_update_tray_menu was called by Gnome2::Wnck::Screen=HASH(0x4040d10)
        full was emitted by widget Gtk2::MenuToolButton=HASH(0x44ea5b0)
        2 Ns used in wild-card
        Searching for files with pattern: (?^u:2013\-01\-29\-\-16\-05\-06__\$nb_name__(\d\d)\.png\.png)
        Searching for files with pattern: (?^u:2013\-01\-29\-\-16\-05\-06__.{1,}__(\d\d)\.png\.png)
        Comparing 2013-01-29--13:51:35__Selection__001.png
        Comparing 2013-01-29--14-03-24__Selection__001.png
        Parsing wildcards for /home/richw/screenshots/2013-01-29--16-05-06__$nb_name__01.png.png
        Parsed $width and $height: /home/richw/screenshots/2013-01-29--16-05-06__$nb_name__01.png.png
        Parsed $profile: /home/richw/screenshots/2013-01-29--16-05-06__$nb_name__01.png.png
        Parsed $name: /home/richw/screenshots/2013-01-29--16-05-06__A__01.png.png
        New uri after exists check: file:///home/richw/screenshots/2013-01-29--16-05-06__A__01.png.png
        Trying to save file to /home/richw/screenshots/2013-01-29--16-05-06__A__01.png.png
        Saving file /home/richw/screenshots/2013-01-29--16-05-06__A__01.png.png, png, 9
        screenshot successfully saved to /home/richw/screenshots/2013-01-29--16-05-06__A__01.png.png, but unable to add the file to session!
        fct_update_tray_menu was called by Gnome2::Wnck::Screen=HASH(0x4040d10)

USER ACTION: quit shutter from Systray > QuiT

        fct_update_tray_menu was called by Gnome2::Wnck::Screen=HASH(0x3049e18)
        quit was emitted by widget Gtk2::ImageMenuItem=HASH(0x30652c0)

**note that there was no error message.**

I've got a workaround for now, but it would be great if the session could be fixed.