Below is debug output from running compiz --replace. I ran this command with the external monitor already plugged in. After restarting compiz, the window decorations draw correctly on both screens.
1) Plug in external monitor
2) Open a terminal
3) Type compiz --replace. UI becomes unresponsive (the mouse still moved around, but I couldn't interact with windows)
4) I switched to another VT to see what was happening. top reported apport was running
5) I switched back to VT7; compiz restarted
@Marco:
Below is debug output from running compiz --replace. I ran this command with the external monitor already plugged in. After restarting compiz, the window decorations draw correctly on both screens.
1) Plug in external monitor
2) Open a terminal
3) Type compiz --replace. UI becomes unresponsive (the mouse still moved around, but I couldn't interact with windows)
4) I switched to another VT to see what was happening. top reported apport was running
5) I switched back to VT7; compiz restarted
steve@aether:~$ compiz --replace dbus.server GLibDBusServer. cpp:579 Can't register object 'org.gnome.Shell' yet as we don't have a connection, waiting for it... interface DebugDBusInterf ace.cpp: 196 Unable to load entry point in libxpathselect: libxpathselect. so.1.4: cannot open shared object file: No such file or directory cpp:103 IBus natively supported. dbus.server GLibDBusServer. cpp:579 Can't register object 'com.canonical. Unity.Launcher' yet as we don't have a connection, waiting for it... dbus.server GLibDBusServer. cpp:579 Can't register object 'com.canonical. Unity.Dash' yet as we don't have a connection, waiting for it... dbus.server GLibDBusServer. cpp:579 Can't register object 'org.gnome. SessionManager. EndSessionDialo g' yet as we don't have a connection, waiting for it... dbus.server GLibDBusServer. cpp:579 Can't register object 'com.canonical. Unity.Session' yet as we don't have a connection, waiting for it... dbus.server GLibDBusServer. cpp:579 Can't register object 'org.gnome. ScreenSaver' yet as we don't have a connection, waiting for it... dbus.server GLibDBusServer. cpp:524 DBus name lost 'org.gnome.Shell' dbus.server GLibDBusServer. cpp:524 DBus name lost 'com.canonical. Unity'
compiz (core) - Info: Loading plugin: core
compiz (core) - Info: Starting plugin: core
compiz (core) - Info: Loading plugin: ccp
compiz (core) - Info: Starting plugin: ccp
compizconfig - Info: Backend : gsettings
compizconfig - Info: Integration : true
compizconfig - Info: Profile : unity
compiz (core) - Info: Loading plugin: composite
compiz (core) - Info: Starting plugin: composite
compiz (core) - Info: Loading plugin: opengl
compiz (core) - Info: Unity is fully supported by your hardware.
compiz (core) - Info: Unity is fully supported by your hardware.
compiz (core) - Info: Starting plugin: opengl
compiz (core) - Info: Loading plugin: copytex
compiz (core) - Info: Starting plugin: copytex
compiz (core) - Info: Loading plugin: imgpng
compiz (core) - Info: Starting plugin: imgpng
compiz (core) - Info: Loading plugin: move
compiz (core) - Info: Starting plugin: move
compiz (core) - Info: Loading plugin: place
compiz (core) - Info: Starting plugin: place
compiz (core) - Info: Loading plugin: commands
compiz (core) - Info: Starting plugin: commands
compiz (core) - Info: Loading plugin: vpswitch
compiz (core) - Info: Starting plugin: vpswitch
compiz (core) - Info: Loading plugin: mousepoll
compiz (core) - Info: Starting plugin: mousepoll
compiz (core) - Info: Loading plugin: resize
compiz (core) - Info: Starting plugin: resize
compiz (core) - Info: Loading plugin: compiztoolbox
compiz (core) - Info: Starting plugin: compiztoolbox
compiz (core) - Info: Loading plugin: regex
compiz (core) - Info: Starting plugin: regex
compiz (core) - Info: Loading plugin: grid
compiz (core) - Info: Starting plugin: grid
compiz (core) - Info: Loading plugin: snap
compiz (core) - Info: Starting plugin: snap
compiz (core) - Info: Loading plugin: wall
compiz (core) - Info: Starting plugin: wall
compiz (core) - Info: Loading plugin: unitymtgrabhandles
compiz (core) - Info: Starting plugin: unitymtgrabhandles
compiz (core) - Info: Loading plugin: session
compiz (core) - Info: Starting plugin: session
compiz (core) - Info: Loading plugin: animation
compiz (core) - Info: Starting plugin: animation
compiz (core) - Info: Loading plugin: expo
compiz (core) - Info: Starting plugin: expo
compiz (core) - Info: Loading plugin: workarounds
compiz (core) - Info: Starting plugin: workarounds
compiz (core) - Info: Loading plugin: fade
compiz (core) - Info: Starting plugin: fade
compiz (core) - Info: Loading plugin: ezoom
compiz (core) - Info: Starting plugin: ezoom
compiz (core) - Info: Loading plugin: scale
compiz (core) - Info: Starting plugin: scale
compiz (core) - Info: Loading plugin: unityshell
compiz (core) - Info: Starting plugin: unityshell
WARN 2014-04-14 11:54:47 unity.glib.
ERROR 2014-04-14 11:54:47 unity.debug.
WARN 2014-04-14 11:54:47 xim.controller XIMController.
WARN 2014-04-14 11:54:47 unity.glib.
WARN 2014-04-14 11:54:47 unity.glib.
WARN 2014-04-14 11:54:48 unity.glib.
WARN 2014-04-14 11:54:48 unity.glib.
WARN 2014-04-14 11:54:48 unity.glib.
ERROR 2014-04-14 11:54:48 unity.glib.
ERROR 2014-04-14 11:54:48 unity.glib.