Let me make sure this is clear: you try to log in and the login
process hangs after you have entered your login name and password?
What does the screen look like at this point?  Is the Red Hat logo
still showing, for example?  Have you checked the logs to see if
any error messages are showing up?  gdm logs X output in /var/gdm;
in your case, the contents of /var/gdm/:0.log would be interesting.
During the hang, go to a text console with ctrl-alt-F1, log in as
root, and copy the contents of /var/gdm/:0.log somewhere and mail
them back to bugzilla (respond to the email containing this message).

closed; lack of input