Dual Monitor issues

Hi to all here, hopefully someone may be able to help out.

I'm running WindowsBlinds v6.2 on an ATI Radeon X1550 dual headed graphics card, to 2x 17in 1280 x 1024 monitors. WindowsBlinds applies the themes correctly and everything there is fine, it's when I start to move some windows from one screen to another I sometimes end up with 'stamped' images from where the window previously sat - to clear them I have to press F5 when I select an icon on the desktop so the desktop 'cleans' itself. Have tried a couple of changes, like the monitor refresh rates (60 / 70 / 75hz) and also the system properties / visual effects properties, and tried turning off 'show window contents' and also on but with the same problem. Sometimes I only have the header bat at the top of the window, say with IE7 from monitor 1 to monitor 2, yet when I hover ove where buttons are they appear. Also sometime shadows under windows appear as  black rectangular areas as if in place of the transparent shadows. I have to minimise then restore the window back to show the content. This is not happening all the time, just seems to be a bit of an issue - anyone else have this problem? I'm currently updating Catalyst Control Centre to version 8.8 to see if that sorts the issue out. Any help with this would be appreciated - can be a hinderance as I use both monitors on a very frequent basis.

Thanks