Outlook looking to old Exchange server

I recently performed an upgrade from Exchange server 5.5 to Exchange 2003.  I did the swing method, where I installed 2003 on a new server and migrated all the mailboxes over, then changed over the internet mail connector to make sure mail was passing to the internet without the old server.  I was going to follow the instructions to delete the old server, but I wanted to make sure I didn't need the 5.5 server so decided to shut it down before deleting it out of Exchange administrator to make sure everything still functioned.  Well, I have 1 client (out of about 50) that is having troubles.  It works fine when the exchange 5.5 server is up, but with it shut down, it acts really strange.  When outlook first comes up, it pauses for about 30 seconds but does come up.  The user can see their email, and even receive mail.  But when she goes to send mail, it will say "Trying to communicate with EXCHG01..." and just hangs.  EXCHG01 is the old server.  In control panel under mail, the exchange server is set to EXCHG02.  Why in the world is this client still looking to the old server?  

Another odd thing about this workstation, is that under Microsoft Exchange Server name in control panel, it just shows EXCHG02 instead of the fully qualified domain name.  All the other workstations have the FQDN but this one, so I'm sure this is related I just don't know how.  I checked ALL The network settings and they match all the other workstations.  Any ideas are appreciated.