Fast User Switching / Welcome Screen requiring logon passwords

[chritophera]

OK...so...this has been happening for a while now and I have gone through everything that I can think of and still no resolve. Here is what is happening.
My wife and I have separate logon screens for Windows XP Pro. Using fast user switching and the welcome screen, she has her account and I have mine. Things will work good for a few days, and then she will leave the PC as normal. The screensaver will kick in and then revert back to the welcome screen when the mouse is moved. Once this is done, she will try to click her user and it will request a password. She can click my user and it will also request a password. The issue here is that we have never set passwords on our individual users.
This issue has also happened when I leave my user active on the PC. The difference being, I have no SS set and the power options on my screen allow the monitor to never shut off. My wife will then go into my user, click Start, then click logoff user and then have the system return to the welcome screen.
Both users are set as computer admins
The option to have the system request a password when resuming from SS is disabled.
Like stated before it doesn't happen all of the time. Only once every couple days or so. My only other thought that I had was to set passwords on both of the logins and then remove them and see if that "tricks" the system.
I'm running XP Pro w/ SP2 and all of the latest updates.

Any help would be appreciated.