furthermore, i can playback flash files or even those stupid flash adverts when i am not mining.
same goes for video playback.
Then the issue is that you're mining (using all your video card) and then trying to use more of the video card. It can only support so much.
Set your intensity down to like 4 (sha) or 12 (scrypt) and you should be fine. I do that for gaming as well.
alright then.
let me google for info on that because i've no idea how to use this cgminer sw.
When you start it, you add a -I flag, right? If you're mining BTC, you'll want -I 4, if you're mining anything else, -I 12. If you are inputting all the server info and such in cgminer itself, push g, then i, then 4 or 12 and hit enter.