[newbie] Can't login after updating PAM

[Brent Metzler]

I tried to upgrade to October Gnome but needed to update PAM also.  I
installed pam-o.68-8.i386.rpm but now I get an error "su: module not
found"
and can't login.

How to fix?

I originally had Mandrake 6 on the box, but upgraded most stuff as it came out.

-Brent