movieman523: I had that problem yesterday. I was running 1.2, and it kept downloading the patch and telling me that my game version was invalid.
I had to manually download the 1.3 and 1.3.5 patches and install those, then it managed to install the 2.0 patch. Given that the auto-patcher told me that I had 1.2 installed I'd have thought it would be smart enough to install the 1.3 and 1.3.5 patches and install those before trying to patch from 1.3.5 to 2.0. Obviously not.