Temporary Profiles loading randomly on XP clients, Server 2003 domain

Hi all,

I watch over a domain of 16 servers and 177 clients, all of which are running Windows Server 2003 SP2 and Windows XP SP3, respectively.

Over the last 1.5 to 2 months, there have been random users (about 25 users now) that have temporary profiles being loaded upon login.  Sometimes when they reboot once, it loads the proper profile.  Other times it takes two to three reboots of the pc's to load their proper profile.  Here is what is common to each user/pc:

- Each user has the same rights/permissions to their pc's
- each pc is Windows XP SP3
- the profiles are not roaming profiles
- each pc is on the domain
- there are two domain controllers, each Windows Server 2003 SP2
- all pc's and servers are up-to-date with all Microsoft updates
- each pc has Kaspersky Anti-virus installed, are scanned weekly, and are clean, controlled by the admin kit, which is installed on a server
- each pc/user is logged into Citrix XenApp upon a successful logon, but no sessions are active until they attempt to load a published application
- each pc is HP or Dell, all within the last 2 years with a minimum RAM of 2GB

There are GPO's in place, but nothing that I can think of to create this issue.  The most important GPO is to map their "My Documents" folder to a shared drive on the file server.
There is not a common piece of software that all users are working with that may be shutting down incorrectly upon logoff, which may cause this either.
There are not any indications in the event logs on the servers or the clients to indicate any problems.
No significant changes have been performed on the network that could be singled out as the culprit.

I'm racking my brain on this and short of logging into each computer and deleting/rebuilding the profiles, I'm not sure what to do as this may keep happening on others.  Any suggestions would be greatly appreciated.

Thank you!