Obviously I didn't know what to call them. Each seems to have a unique meaning but also seem to be used *very* loosely!
I am running as administrator so that didn't help.
Changed the Behaviour to 'Switch to the respective desktop' and that seems to have taken care of things. At least Outlook is only open on Desktop 1 now. (( Gonna have to do something I *never* do and that's look at the documentation .....
Thanks for the quick reply //al

If some programs are always visible on all desktops: [FAQ] Some windows appearing on all desktops on Vista/7

If they remain on a single desktop initially, but wander to other desktops over time, try the option "Behavior of windows on other desktops" at "Settings > Plugins and Extras".

PS: We call them desktops - not screens, views, or displays.

I really like the ability to have multiple views, as one does in Linux so I've been trying out Dexpot on my Win 7 / x64 system and find that too many programs, once started in one display seem to duplicate themselves across the other displays. Winrar, when I ran it yesterday, and Outlook, which remains open are present on all views.
Can you offer any suggestions that I might be able to use to keep them to just the one view on which I start them??
//al