Secondary Monitor FPS

[Exige]

I've had my monitors for quite a while now, both are Hanns-G 21" Widescreen LCD's. I normally play my games on my primary monitor, so I've never noticed this before. But, today, I was playing on both my monitors. Normally, while running a game two times the frame rate is going to suffer, but after I closed out one of my games, I noticed that my frame rate was still pretty bad. About 30fps, on my secondary monitor. (60-80fps normal, when running the game on both monitors it's about 30fps each.) So anyways, I noticed the frame rate deficiency, and for some reason immediately thought it was because I was on the secondary monitor, I shrunk the window and brought it over to the other screen with the frame rate counter up, and it literally ran up from 30fps to 60. Dragged it back, and it dropped again.

Very weird, I didn't ever think about this happening when I got the set up. Is there something I can do about this or do I have to live with it?

Thanks in Advance
-Amo