HELP. I can't login as root !!!

[Brendan J Simon <brendan.simon@bigpond.com>]

Please help.  I can't logon to my system as root.  I'm running testing 
on a AMD Athlon 1600XP machine with 256MB RAM and 40GB hard disk.

I used to be able to login but I upgraded some packanges and now I can 
not login as root on the console nor via gdm.  I can login as a normal 
user but when I try to "su" I get a segfault.  The password is 
definately correct as I get different responses for wrong passwords. 
When the password is correct I see the welcome to Debian 3.0 message 
but then it throws me straight out.

Please help as I can not do any more apt-get upgrades or other sys admin 
maintenance.  Please reply to me with "reply all" as well as the list.

Thanks,
Brendan Simon.