Hey there Mac friends. So Steam for Mac is great, and it's getting better all the time with new games coming all the time! Left4Dead 1 got released today, which I am very happy about. One problem that's been bugging me though. Why can't I run L4D2 on high graphics on Mac OS X like I could on Windows XP on the same mac! Is it the Mac OS X drivers, or something else? Anyone else got the same problem?