Remote Desktop Logs me off

I have a machine running windows server 2003 that has acquired a problem recently. When I logon to remote desktop (without a terminal services server, it will allow 3 users including the console session) it logs me off as soon as it finishes the logon process.

This is somewhat irritating, to say the least, and I can't put together any google search terms that give me anything helpful.

Does anyone know what I can do, short of reinstalling?

Is there any logs in the error log? Does it give you any errors?
Are there any other RDP sessions open (disconnected) that are taking up the available connections. If so, you can have them auto close by configuring the options in term svcs console...

no logs, no other rdp sessions open.

To make sure it's clear, it DOES let me log in, it just logs me off again right away/

Do you have the server in application server mode or remote admin mode?

http://www.certyourself.com/index.cfm?pageid=131

there is some good info there, not sure if any will help you though