Reminders in Outlook

I have an corporate XP customer who keeps receiving an error message while in Outlook 2002 that says their ‘reminders cannot be displayed, possibly because of a network problem with the exchange server.’ However, no reminders have been set, and there is not a problem with the network connection; the user is recieving and sending email with no problems. There are items in the calendar, but I disabled all reminder notification settings in Outlook to see if this corrected the problem – no luck.This message appears several times thoughout the day, for no apparent reason, and has not occured on any other machines that are connected to the same Exchange Server.