Yeah, you could either have a faulty monitor, or a faulty graphics card, one of the two, or it could be drivers...
Can you first of all test the monitor on another PC?
Next if this doesn't work, go to step 2, if it does, go to step 3
Its the monitor causing the problem
Its either the video card or the drivers
Hopefully its the drivers, so go to the nvidia site and download the latest drivers for that card, or batch of cards (usually the case)
and install them instead.
Then try that, if that works good
If not, go to step 4.
Its the graphics card itself, I'm afraid you'll have to either ship it back or use a guarantee if you still have one
Sorry, but at least you know thats the problem now!
Hope this helps