Look For: does not work in Inbox

[jerryk]

When I enter something in the Look For: box in Outlook 2003 and press Find
Now, I get an error "The messaging interface has returned an unknown error.
If the problem persists, restart Outlook." I have restarted Outlook; it did
not help. I tried starting Outlook with /safe option; that did not help. If
I try this on an archive folder, it works fine, but not the Inbox, Deleted
Items, or Sent Items folders in the Mailbox.

I am using Exchange.

Thank you.
JerryK