Thanks for this additional information. So it looks like this may be the fallout of some filesystem corruption. You can try to reinstall gconf2 and see if that helps, but given the situation it maybe better to backup your data and reformat/reinstall.
Sorry, michael P.S. I will close the bug now, because there is little that update- mangaer can do here. ** Changed in: update-manager (Ubuntu) Status: Unconfirmed => Rejected ** Changed in: Ubuntu Status: Needs Info => Rejected -- Could not install the upgrades https://launchpad.net/bugs/96452 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs