Mick,
I had the same thing start about a month ago with Office 2000,
using Winows 2000. If you see this, please respond with a little more
info cause it looks like no one else is going to answer you. I have a
laptop also with Office XP and I did not get double copies of emails on
that computer. It's easy for me to compare them because my ISP is set
to retain the email on their server (so I can independently download
the email to both computers; I have no idea how to syncronize the two
computers any other way). Periodically, I go to the attglobal web site
and erase all the emails. Anyway, point is that double emails appear
on the Office 2000 machine but not on the Office XP machine. The only
other difference between the two machines is I loaded a nifty little
free utility called Plaxo on the Office 2000 machine. I started
getting double emails shortly after installing Plaxo. Their support
staff says no way is it their problem. Are you running Office 2000 or
do you have any 3rd party utilities added to your Outlook?
FrankW