gdm login is broken in unstable(?)

[Miles Bader <miles@lsi.nec.co.jp>]

As of today I can't login via gdm anymore; it accepts my userid and
password, restarts X, and then just restarts X again and shows the gdm
login dialog.

/var/log/auth.log shows something like:

  Apr 12 10:44:28 mcspd15 PAM_unix[8872]: (gdm) session opened for user miles by (uid=0)
  Apr 12 10:44:29 mcspd15 PAM_unix[8864]: (gdm) session closed for user miles

/var/log/XFree86.0.log shows nothing unusual (no error messages or
anything).

Another message on this list (subject `startx not working') mentions a
similar problem, and someone replied that the `libpam0g' package was
somehow involved; I tried replacing that package with the version from
testing, but the same problem still occurs.

Does anyone have any idea how to work around this problem?  I'd really
like to use X!

Thanks,

-Miles

p.s. Please keep me in To/CC; I don't read this mailing list directly.
-- 
Love is a snowmobile racing across the tundra.  Suddenly it flips over,
pinning you underneath.  At night the ice weasels come.  --Nietzsche