I just tested OpenGL on Windows 2000 prof with the same setup - problems were there as well.
OpenGL apps run fine for a few seconds, then freeze for half a minute and then work fine for a few seconds again. This is basically similar to the behavior in Linux, but at least it does not crash the system. (Windows driver 43.45).
I am beginning to doubt that there is a chipset/card/driver -problem going on :-|