Is it a laptop or desktop? I'd really need to see the problem first hand, but I suspect it's getting some kind of interferrance. If it's a desktop, try moving the wires around some, maybe switching wires if possible. If it's a laptop, try moving the screen a bit and see if it clears up.
I think most Compaqs carry a year warranty. You may want to contact Compaq before diving too deep and risk voiding a warranty.