It looks like my failure (with Intel graphics) was indirectly caused by problems with startup scripts, as described in bug 430125.
-- Can't start X through gdm or startx https://bugs.launchpad.net/bugs/430031 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
