Only one user can't log into my Fedora 14

Question

I have three users on my system

1. me
2. server
3. misc

From the GUI, I can easily switch between 1) and 3). However when I try to switch to 2), it asks for the password. The screen goes blank for some milliseconds, and again the switch user dialogue appears with another already logged in user (1 or 3).

I'm out of ideas how to solve this.