How did you "upgrade" and from what?
How did you migrate your data to this new installation?
Have you tried repairing your Outlook data file?

Signature
Russ Valentine
[MVP-Outlook]
> Ever since I upgraded to Outlook 2003, I am unable to open certain
> contacts
[quoted text clipped - 7 lines]
>
> Thank you.
Upgraded from Outlook 2000. If I recall, the setup migrated the contacts
automatically. I'm not sure how to repair my Outlook data file??
> Ever since I upgraded to Outlook 2003, I am unable to open certain contacts
> without a dialog box popping up saying "Could not open one or more
[quoted text clipped - 5 lines]
>
> Thank you.
Russ Valentine [MVP-Outlook] - 11 Sep 2007 21:54 GMT
Upgrade installations of Outlook are not recommended. Two things are
necessary for Outlook to work after an attempted upgrade installation.
1. Repair your Outlook data file using the Inbox Repair Tool (scanpst.exe)
http://support.microsoft.com/kb/272227/en-us
2. Create a new profile from scratch:
http://support.microsoft.com/default.aspx?scid=kb;en-us;829918&Product=out2003

Signature
Russ Valentine
[MVP-Outlook]
> Upgraded from Outlook 2000. If I recall, the setup migrated the contacts
> automatically. I'm not sure how to repair my Outlook data file??
[quoted text clipped - 11 lines]
>>
>> Thank you.