Outlook 2003 on Tablet search folders?

The search folders in Outlook are not working properly post SP2 on a Sharp Tablet PC. When I read an e-mail message from the ‘Unread Mail’ folder, it stays in that folder even after I’ve read it. I can even open and close outlook and the message stays in the unread folder. If I delete the message from the unread folder, it deletes the message from the inbox folder as well. Any suggestions?