POP3 Crashes Store On Exchange 2K

Environment:
Windows 2K AD DC SP3 on srvr1
Windows 2K AD DC SP3 on srvr2
Windows 2K SP3 running Exchange 2K SP3 on exch1
AD single domain/forest
exch1 is the only Exchange server.
Exchange is setup to allow POP3, IMAP, OWA (web), and SMTP.
All in house users use Outlook as an Exchange client. Outside users use either POP3 or OWA (whatever they want).
POP3, IMAP, and HTTP (OWA) is enabled on a user by user basis (not everyone has access). POP3 is configured to use Basic Authentication. HTTP is configured to use intergrated.

Problem:
For most users POP3 works fine, however I have one user that when ever he tries connecting using POP3 it fails and the

Exchange Information Store (IS) crashes, and by that I mean that the servicestops.
I have tried searching but couldn’t find anything on this.

Continued…..