Bug#76537: project: gdm's PreSession/Default relies on sessreg which is no more in xbase-clients.
I just updated my system (apt-get -f dist-upgrade) and got the new X4.0.
After restarting gdm it didn't let me in no more 'cause the
/etc/X11/gdm/Pressesion/Default tries to start /usr/bin/X11/sessreg which was
formerly in xbase-clients, but seems to have dissapeared.
I hope this wasn't due to a misconfiguration on my half :-)
-- System Information
Debian Release: woody
Kernel Version: Linux stm-7 2.2.15 #1 Sat May 13 10:22:03 EST 2000 i686 unknown