I have a 2.80GHz dual core processor, 1GB RAM and a nVidia geforce 8600gt. I've played Grundorf map and it runs very smoothly, so is the Berlin-Spandau (Old) map. However when I recently downloaded the New Berlin map, it was not only lag, but halfway through the game, my windscreen and side windows turned black and I can't see what's going on outside. So was it a problem installing the file or a computer that cannot handle the graphics? Thanks for any help rendered.