is it a LCD monitor or a CRT one?
If it's LCD are you running it in the native screen resolution for the monitor? as running it in a lower res means the monitor will be stretching the image to fit the screen and this can cause the effects you describe.
(and you are always better off using the proper drivers for the card rather than the windows native ones, even if you don't play games the scrolling of documents and web pages will probably be very jerky with the standard XP VGA drivers)