I was able to solve the problem. It is probably related to unadvised partial upgrades I and others did. Explanation:
At least in my installation two packages (libgnome-window-settings1 2.30.0-0ubuntu3 and capplets-data 2.30.0-0ubuntu3) were being held back from updating. Both are probably dependencies of the current gnome- control-center package, which consequently, I figure, was also being held back, even though aptitude apparently didn't report so. I had to force the installation of these two packages. It resulted in the uninstallation of the ubuntu-desktop metapackage and then of gnome- control-center, which is part of ubuntu-desktop; so after updating libgnome-window-settings1 and capplets-data I simply had to reinstall ubuntu-desktop. gnome-appearance-properties works fine now. -- gdk_display_sync: assertion `GDK_IS_DISPLAY (display)' failed https://bugs.launchpad.net/bugs/518368 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
