I just got Prey and whenever a grenade is thrown and explodes, the game freezes and freezes my entire computer. I easily meet the requirements. MacBook 2.4 GHz Intel Core 2 Duo 2Gb of Ram plenty of hard drive 144MB of Vram the only thing that isn't compatible with the info on the box is that instead of a ATI or NVIDIA video card I have the factory installed GMA 3100. Could that be the problem? Any other ideas?