So I recently installed ArmA off steam but I immediately ran into a serious graphics issue with the vegetation, most of it is really, really bright, in stark contrast to everything else, and as you say, fly past it on the training mission, different bushes keep disappearing and reappearing as you pass by it, its absolutely horrible.
Picture of what I mean:
I'm using a ATI Radeon HD 4800 Series with latest drivers. Any ideas?