Gamma & Direct X 9Follow

Ok here is the problem....
I upgraded my video drivers and then downloaded Direct X 9. Now both mine and my hubby's EQ only plays correctly in full screen mode. When I Alt Tab out to windows I loose Gamma control (the slider does not function) and it becomes very dark (sometimes to dark to play). It restores it self when I return to full screen mode (which can take a few seconds and can be dangerous in combat). Any ideas??
It was working just fine until I upgraded to Direct X 9......