Currently gdm tries to ensure that the user's home directory exists before initiating the login session. This causes problems in situations where root doesn't have permission to know about the existance of the user's home directory (because of root squashing nfs, ACLs, etc...). GDM should first seteuid/setegid to the user before testing for the existance of the user's home directory. Note this bug is the same bug as Bug 149580, but for tracking the RHEL-4 erratum instead of RHEL-3.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2005-151.html