That one worked fine for me for DOSBox in Win7 RC1 x64. I'm currently using the 190.56 drivers from here: http://developer.nvidia.com/object/opengl_3_driver.html

Does it happen with Rayman demo too?
If I understand correctly you describe some sort of screen tearing issue?

Edit:
Is it something like this?
http://en.wikipedia.org/wiki/Page_tearing

A screenshot would really be nice...

Try the windows printscreen if the bug can't be seen on DOSBox captures.

HunterZ: I cant use those drivers =( they're for geforce 8 series and up, and i'm at 7800gtx..

Miki Maus: yes, this happens to the demo too, unfortunately.. and yes, it seems that this may be a screen tearing issue, however; it's not exactly like what you see on the picture on wikipedia or something 😜 it's like a thin line (about 1cm) that just bugs a little... this line is moving downwards at a slow rate at all times.. it takes about 5-6 seconds for it to cross the screen. And the buging jumps forward and backwards where the line is..

h-a-: i find it extremely difficult to get a screenshot of this, dunno why.. =(

EDIT: and also! this problem doesnt occur in the opening animations! only ingame and i can sometimes notice it in the loading screen..

Have you tried lowering Hardware acceleration and unticking "Enable write combining" in Troubleshoot section of Display Properties-Settings-Advanced window?

Tried that, didnt work.. =/

What are your vsync and triple buffering settings in the nvidia control panel? Does this happen both in a window and in fullscreen?

problem solved! I had forgot to force the vsync on, and that's why the problems occured! now that i have vsync on, everything works perfectly! 😁 thanks alot 😁:D:D
I have the triple buffering turned off.. with it turned on, the problems came back.

Yeah, triple buffering is actually the best option for programs that specifically support it, but for many that don't it seems to give the same result as disabling vsync.

I actually solved it with enabling vsync 😜 hehe