I installed it on steam, and started playing the game.
Result? Constant 60 fps, 1920x1080 resolution and no problems at all (besides the slight texture popin but it's almost not noticable). It's working great for me!
In case you are wondering about my specs:
Win 7 64-bit
8 GB RAM
ATi HD 5850, driver Cat. 11.8
AMD Phenom 965 x4 CPU

as my computer should have been able to run Rage from day one. In a sick way I was lucky as I knew Rage could run stable due to my husbands computer. It took him 14 hrs to play it in single player and get it done and it took me 6 days just to be able to play
The kicker is my box is stronger and faster then the husbands computer and yet I had the issues 