Mark as Read not working

[David]

I'm running Outlook 2002 - SP2, displaying the Preview pane in my
Inbox. If I scroll thru new messages in my inbox so that they display
in the Preview pane for at least 2 seconds (my setting), the message
icons are properly updated to show they've been read. If, however, I
open a new unread message and delete it, advancing to the next
message, the deleted message shows up in my Deleted folder marked as
Unread (even though I had opened it and read it).

Any idea what's going on?

Thanks