Comment 2 for bug 184992

This problem reappeared recently with Hardy and the current situation has nothing to do with X, but DOES have to do with the permissions in /tmp. Creating a new user which solved the previous problem also creates new entries in /tmp for that user and that would have addressed a possible permissions problem with starting X and KDE as that user.

In the current case, with Hardy, after about 3 weeks without reboot on a laptop with multiple suspend/wake sessions a day, the battery finally ran out and the machine rebooted. X would not restart, so I went thru 2 hours of xorg.conf gymnastics, almost all of which gave the same error as above:

(EE) fglrx(0): [drm] failed to remove DRM signal handler

This error message is almost Microsoftian in its passive-aggressively accurate misdirection.

Whatever happened, the /tmp dir was marked root write only, which prevented any user from writing to it (and therefore I'm guessing failed to remove a previously written file somewhere in the /tmp tree form getting removed). So X refused to start up as that user but would start as root.

The solution was to make /tmp writable for everyone.

I still don't have the exact file that was at fault, but the fix is easy enough:

sudo chmod ugo+rwx /tmp

Best
hjm