Thanks for the answer Axelion, but the problem he has in that thread is not what I have here. He has green dots and stuff but i only have transparent black lines going from the bottom to the top, like if you try to watch something on the television but the reception isnt quite there. And the lines you see are black/gray.
What i wonder most about this tho is why does it go away when using vsync or using a dvi cable instead of vga?
Where else do i turn for an answer to this if no one here knows?
Yes thank you for the answer.
Alltough i did write that i have already sortof solved this problem by indeed trying a DVI cable.
But what i was interested in as i wrote was what causes it? Why did it work flawlessly with this vga cable with the gtx460 and hd 6950, but not gtx 580?