MAPI error: 32026- Not Supported

One of my users (out of about 700) received the following error using MS Outlook 2000 SR-1 when she received her new computer:

The current action is not supported by the underlying mail system.

This is what is listed in MSDN documentation...but that really doesn't tell me a whole heck of a lot...especially since all of us here use the same version and service pack of MS Outlook 2000.

Not too sure what to tell her other than to have them reinstall MS Outlook 2000. Any ideas out there in VB Land?