Unresponsive logoff Windows XP

Hello:

I just installed a new network, configuring two new Dell
workstations on a network running Windows 2003 Standard
Server. I am experiencing slow or unresponsive logoffs
on one workstation.

The user accounts are using roaming user profiles and
some users are experiencing intermitent logoff problems
on one workstation. It may take two to three attempts to
initiate a logoff sequence and during the system "hang"
the Ctl-Alt-Del will not initiate the task manager in
order to determine which application is not responding.
In reviewing the Event Viewer, I fail to see any entries
regarding the cause of the slow and/or non-responsive log
off.

Any ideas as to troubleshooting this problem? Any help
would be appreciated.