Hi Keyclone...

Ok I had the same issue with 1.7t06dec but managed to resolve it by setting the resolution of my main window to 1 pixel less than the screen width 1919x700 works fine but 1920x700 has too slow a refresh rate.

My system is set up with a Radeon X1950XT (512mb) for the 24" monitor @1920x1200 and a Radeon 2400Pro running 2monitors @ 1200x1024 and 1024x768
situated as follows