Windows User Account Locked for No Reason

Hello, I have a user that is getting locked out 9 or 10 times a day for no reason. We have reset her password, changed it back to her old password, disabled and enabled her user account, reset her computer account, renamed her PC, rejoined the PC to the domain, restarted the PC and still no matter what she gets locked out even when she is not asked for her password. Windows 2000 domain, Win XP box. Any suggestions?