Check Names with Personal Address Book

When I type a name from my Personal Address Book it auto completes the
spelling but when I then Check Names or try to send, it doesn't find
the name and brings up the Check Names box with no suggestions. If I
click To, the Personal Address book shows up first and I can
successfully choose the same person. If I use a name from my Global
Address List, it works fine in all respects. I am running Outlook
2002 SP-2.

Any theories?