When I click on the Mail icon in Control Panel, select the Data Files tab,
choose any data file and click Set As Default, I get the message:

An unknown error occurred, error code: 0x8000ffff.

This occurred after updating from beta 1. I successfully ran the Inbox
Repair Tool on my .pst file, but still couldn't get around this problem. I
also tried creating a brand new .pst file.

This error prevents any meaningful use of Outlook. I can't Send or Receive
messages, view contacts or calendar. For some strange reason, I CAN view my
Inbox.

Any suggestions would be greatly appreciated!

Marc