I imported my contacts from a PST file and they appear in the Contacts
folder. When I click on the TO button when composing an email I get an error
that the address list can not be displayed. If I click on the Options on the
tools bar and then the Contacts button they're there.  I tried the steps at
this URL and it works until I exit Outlook.  Then the problem returns.

http://support.microsoft.com/default.aspx?scid=kb;en-us;287563&Product=ol2002