There's a very similar bug in maverick, see Bug #746796. The important part of the problem seems to be that we upgraded from a backported gdm version to a security update gdm version. See Sebastion Bacher's comment in the duplicate.
** Changed in: gdm (Ubuntu) Status: New => Confirmed -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gdm in Ubuntu. https://bugs.launchpad.net/bugs/746694 Title: GDM_LANG overrides my locales -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs