I just uploaded the 0.4.6 for Windows:
v0.4.6 Alpha
- Extended the alpha to June 1, 2011.
- Patched several problems with ATI cards.
- Removed the version from the 3dsmax's plug-in filename because it was causing some duplicate GUID messages. Newer versions will just overwrite the file.
- Fixed a color mismatch between 3dsmax and the standalone renderer.
- Now the plug-in for 3dsmax uses the 3dsmax's gamma settings.
- The gamma slider have been removed from the ratGPU's config dialog.
- Recompiled using the latest libraries.
I've patched it for ATI cards. Now it does not hang as the previous 0.4.5... but the problem is not really fixed, there's a bug in ATI's OpenCL JIT compiler that makes ratGPU to render at half the speed it should...