My opengl doesnt work on dual monitor.

I am trying to find a combination of two adapters that will work with opengl. I want the ability to drag an opengl window over to the other monitor and it still function. So far on most of my computers, when I drag to the other monitor, it freezes. I am either looking for a dual head agp card that will work or a pair of PCI cards that will work. Does anyone have any ideas?

Here is some basic (and perhaps outdated) info: