Indeed. I have purchased three video input cards and returned them because they were too laggy. The one I finally ended up using (made by ATI) is only playable with old drivers. I reccomend getting a direct connection from the PS3 to your monitor. In my case, I got a Composite/Component/S-Video to DVI converter from DVI Gear, though that would probably be less than optimal for the PS3.

How did you try to connect the PS3 to your monitor?