I have a Gateway laptop and run it dual screen with a 19" TFT plugged in to it. The TFT is fine when plugged into my normal PC but when using the VGA out port on the laptop the screen is distinctly fuzzy.
I am running it at it's native 1280x1024 and 75Hz.

Has anyone else experienced this?

I would check to see if there was a new driver for that display. It is possible it could be the vga cable (or dvi/vga adapter if you're going that route). I assume you checked over the settings for the extra display, but did you look for a newer driver?

I have usually only see this when you run a secondary monitor to low or high of a resolution, I would try first to reduce the resolution to as low as possible, and then as high as it can go and see if it improves.

If that doesnt work, swap out a vga cable.