What CD drive are you using (maybe need a CD driver update O.O....
And it may also be that you just have a bad copy of the CD, check the guidelines of getting another copy.
Well, honestly guys... I get about 40-50 frames per second, and it is fine. 60 frames *shrug* Anyone play Quake when it first came out? Anyway, it also maybe the fact that phsyics calculations are making it hard on the PC.
Steam used to suck, now it's relatively sane to use, and really.. it's isn't that bad. I don't like the idea of registering keys to a login though, as transfers are difficult and lending all legal rights of the liscence you purchase to someone else is almost impossible.