Default Printer Selection

I am supporting several Terminal Server installations for several different
organizations. At least two of these organizations are having the same
problem. When the user selects a default printer from the Printers & Faxes
applet, that printer remains the default only during that session. After
logging off of the thin client session and logging back on (typically the
next day) the default printer has been reset to a different selection. What
would cause this to change?

The terminal server at both organizations is Windows Server 2003. The file
server at one is 2003 SBS, while the other is running Windows Server 2003.

Any suggestions are greatly appreciated.

Thanks,
--David