Thanks for this additional information. I have not seen this error yet in lp/ubuntu and the explaination that it might be due a 3rd party install makes a lot of sense. I close the bug therefore.
The output of: $ ldd /usr/bin/gtk-update-icon-cache would be interessting as well. Thanks, Michael P.S. Try reinstalling the ubuntu version of libpng and run dpkg --configure -a; apt-get install -f ; apt-get dist-upgrade ; to recover your system. ** Changed in: update-manager (Ubuntu) Status: Needs Info => Rejected -- Edgy-Eft to Edgy 6.10 - Could not install gdm and gnome-panel-data https://launchpad.net/bugs/61897 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs