The patch 002_xdm_fixes.diff (at least the version
714 2003-10-25 01:35:48Z branden in 4.2.1-16) removes the ability
to lock the PID-file. (The part within the "if (lockPidFile)") and
instead stops starting if there is any file at all. This causes xdm
to not restart when it terminated abnormally or otherwise left
the pid-file. (Which is does very often here.)
Alternatively some paramter to make xdm not looking at the pid-file
at all would be nice, so that something like my /etc/inittab line
9:2:respawn:/usr/bin/X11/xdm -nodaemon
would again work around xdm terminating so often...