Fail to load login screen

[Jbs63]

I just installed a new login screen and when I restarted x it never loaded. so I cant login to change it back. is there anyway I can boot ubuntu in safe graphics mode or change the login screen via the terminal

[Jbs63]

I found this thread http://ubuntu-utah.ubuntuforums.org/showthread.php?t=10058

Didnt work first time so I dismissed it. Turns out I just had to delete some file in /tmp

sorry for clogging up the forums :P