Account Lockout when new mail arrives (some of the time)

We have only a few users that have this problem but it won’t go away. They will complain of an account lockout as low as two or up to 20 times times a day at about the same time a new email will come in.

Mixed environment of Office 2000 or 2003 on XP PRO clients. All pcs are fully patched/up to date, no rogue services, programs, spyware, viruses, no offline email settings.

It is or appears to be client based for sure. If they run their email via a remote desktop session on one of our Terminal Servers – they don’t seem to get locked out. One poor user has been plagued for over 45 days with this – once our VP got it – it became a higher priority.