My Westinghouse 22in wide monitor looked better with the analog cable on a GeForce 5200 video card. It even gave higher resolution 1690. Now with the DVI cable it's 1440 and looks less bright and detailed. Is it possible an anolog cable could be better ? Thanks

Screen card problem. Chances are that it's not powerful enough to make the most of the DVI technology. Try updating your screen card drivers first.