I will check that out but I'm not very optimistic. The problem is quite random. Happens to some users some of the time. I can find no pattern in the logs. One thing that seemed to be a possible connection was the user getting their password wrong upon first login attempt and then correcting it. But looking further, it does not seem to be related as a user experienced the problem one day when they used the wrong password and then again the next day when they put the password in correctly.

Is there a resouce that lays out the process of a Windows XP Pro login to a Windows 2003 server? It seems like a step is being left out?