ok i figured out my problem. it might work for you too
download the ati tweaker like mentioned above. and when its in the taskbar near the clock, right click on it. go to hardware then overclocking settings.
now the thing is NOT to over clock it but to underclock it (if thats a word)
go to the sliders and adjust the core speed and the memory speed BUT GO TO THE LEFT. if you go the right youl screw it up even more.
now, to test the tears on the screen like in the screenshot, when you have the sliders lower.
( for counterstrike source i use: core: 335 and mem: 331)
adjust the sliders to that. it should work for every new game out there. (not sure about bf2 though)
then click apply.
you should see a button above it called BENCH!
click it. DONT MOVE YOUR MOUSE! it messes it up
watch the box, if you see any tears, lower the sliders. if you dont.. well you should be good.
and to keep these settings. click the save as then name it. and then click load profile on startup.
there ya go. that should fix it.
please let me know if this helped you or not :]
have a good one everybody