Outlook 2002 Contacts won't show as an e-mail Address Book

We are an Exchange 2000 environment. Users have MS Office 2002 and use Outlook to view their email. Things have been working well for 4 years. Suddenly I have a user who cannot view their Contacts when choosing people to send mail to when composing a message.

I know there is a check box under Contacts properties that allows the user to choose to show their contacts as an address book. But this check box is greyed out for this particular user. This happens on any machine that this user logs in on and to the best of my knowledge this is the only user out of 125+ users that suddenly has this problem.

Does anyone know how to give the user permission to check that box under Contacts properties?

Thanks in advance.