Dual Screen in linux

I just put a "All in Wonder 9600 XT" in my Fedora Core 4 computer, and
the "Dual Screen" feature doesn't seem to work properly. And ATI isn't
exactly a supporter of linux, when it comes to documentation.

At the login screen, it works fine. But when I'm logged into Kde 3.5,
it doesn't work. The mouse cursor won't go from one screen to the
next. Is it possible that this is Kde? Or is it X?

I am using this driver:
https://support.ati.com/ics/support/...e&folderID=300

Also, I remember a way to set it in Kde, but i can't seem to find it.
It was called 'Dual Head', or something like that.

But i think it may of been moved or something, since earlier versions,