I have one user whose nickname file bombs every 3-4 months. It's too regular
to be coincidence. The file isn't corrupt and there is data in it but it's
like Outlook doesn't see it.

He keeps having to rebuild it from scratch. Outlook 2002 with Exchange 2k3
fully patched runnin on XP SP3 fully patched.

Any ideas why this is happening and how I can prevent it from happening again?

TIA