login failures today

[William Murray]

   Hello all,
          I have a weird failure on FC5T3. It was fine on Friday, but
today Login fails, for gnome/kde/xfce, and also gnome safe, but not for
a terminal failsafe. I can still ssh in from a remote machine, and watch
the login, but it just hangs after the gnome splash is brought up but
before any icons appear on it.
    I made a new account - and that works fine. So it is connected to my
account settings.  But removing .zshrc doesn't help.

If I 'su' from the new account I see an error:
 find: cannot get current directory: Permission denied
but it is trying to examine a directory called '.'
if I 'ssh -Y XXX at YYY' I can log in OK, but if I try to start
firefox I get: 


*** glibc detected *** /usr/lib/firefox-1.5.0.1/firefox-bin: realloc():
invalid
next size: 0x0a1d1550 ***

followed by a backtrace. 

I don't want to scrub the account completely. Can anyone suggest how I
might fix this?
   Thank you,
      Bill