Tablet PCs Violate Trust

Server is running Windows Server 2000 with a total of 13 workstations: 6 wired and 7 wireless. The wireless workstations (W2K) were recently swapped for tablet PCs (XP Pro). The previous wireless workstation names were removed from AD on the server and the new ones added. We are trying to add users to the tablet PCs and get a trust violation error. What would cause this error and how do we get user accounts onto the XP Pro tablets?