I had this problem many times with Outlook 2000 and begged for help. I got
all kinds of advice -- mostly along the lines of software for deleting
duplicates. But nobody gave me the solution. The only thing that brought
this problem under control is a work-around: Before launching Outlook run
the task manager. The chances are you will find a copy of Outlook running
already. Kill it before running another. For some reason Outlook got into
the habit of not exiting properly when you thought you were exiting so there
got to be 2 (sometimes as many as 4) copies running. It's a Microsoft bug
that never go cured (I even get it sometimes with Outlook 2003).
