I had the same problem where I did a fresh dapper RC install and gnome did not start. The problem was solved by removing the user from audio group. If you add the user to the audio group again and the log out and try to log in again, it will fail again. If there is a solution for this please let me know. Take care all.
-r -- Background displays, but gnome panel doesn't start https://launchpad.net/bugs/43951 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs