It is not your problem. RF G2 is a really bad 3d simulator. I can't hover on G2 more than 10 seconds. Don't worry, at the field is much easier... If u want to train hovers on a simulator buy aerofly pro, it is really good simulator, even in 3D situations. I heard that Reflex simulator was a excellent physics simulator, but i never tryed it. But i personally have G2 and aerofly pro! and i can guarantee that aerofly pro is much better(in everything)... well, u dont have races, and try to pass between 2 points... but... who cares?
Try to download aerofly pro videos from http://www.aeroflypro.com/ and see what im talking about