Greeting MacRumors! Sorry if this is a known problem, I did a brief search but I don't have much time. Since the 10.5.7 update, I have lost the ability to switch GPU's on my uMBP. The option to choose which GPU to use has vanished from energy saver and I also seem to have lost the ability to manage the screen brightness. The on-screen graphic appears when I use the brightness keys, but it is jammed at full. Has anyone else experienced this and/or knows how to fix it? Regards Picturesque p.s I'm fairly certain the active GPU is the 9600, just based on my framerate in WoW.