This problem does not seem to be limited to GParted. It also occurs for GNOME-Control-Center, and Banshee.
See: GLib-CRITICAL **: Source ID was not found when attempting to remove it - warning when leaving Network menu of g-c-c https://bugs.launchpad.net/ubuntu/+source/gnome-control-center/+bug/1264368?comments=all -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1307201 Title: (gpartedbin:6851): GLib-CRITICAL **: Source ID 54 was not found when attempting to remove it To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gparted/+bug/1307201/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs