I don't think, this bug is a duplicate of bug #266911.
It does nothing with the fglrx issue and the fix, described in the bug #266911 didn't work for me.
I would also notice, that if I move mouse immediately after clicking to "guest session" (before the system halt), I get back to the previous login - in my case, I have to login the same way as after I abort screensaver (I have automatic screen locking set)
I don't think, this bug is a duplicate of bug #266911.
It does nothing with the fglrx issue and the fix, described in the bug #266911 didn't work for me.
I would also notice, that if I move mouse immediately after clicking to "guest session" (before the system halt), I get back to the previous login - in my case, I have to login the same way as after I abort screensaver (I have automatic screen locking set)