Can't run X after upgrade

[JD Kitch <adahma@gmx.net>]

I'm currently running a Potato install that I've "upgraded" to the
Progeny beta.  I ran an update earlier today and frankly I didn't
pay much attention to what all packages updated, but something must
have changed related to X, because now I am unable to run X as any
user but root as seen below:

X: user not authorized to run the X server, aborting.

I've tried the old delete of .Xauthority, and it was promptly
recreated but still didn't work.  I've verified /etc/X11/Xserver is
usable by Console.  What else could I check?

Thanks!
jdk