I recently bought a new graphics card when this problem showed up, but I will get these faint white lines, they are static like, not noticeable unless you are on a blackened screen or page, or unless your looking for them. Could the graphics card not be in all the way? Take it out and put it back in? I have a dvi-vga adapter in aswell. Graphics drivers are up to date.
To change the monitor refresh rate right click on the desktop, select personalize, select Display (in the "see also" bottom left of screen), Change display settings, Advanced settings, in the box that pops up select monitor, and the try different screen refresh rates.