Completely rid yourself of freezes!
While I had no more random freezes in 10.6.*, upgrading to Lion allowed for full stability and full use of graphics acceleration via OpenCL/CUDA/OpenGL. So please, upgrade to Lion, go purchase it on the App Store. http://itunes.apple.com/us/app/os-x-lion/id444303913?mt=12
But... But... That's illegal!
Actually, no, it's not. I'm not selling, nor condoning the use or creation of a hackintosh. If you however, are a hobbyist and are curious, the GTX 460 family of nVidia graphic cards now work in Snow Leopard (osx86).
All one has to do is go here and download the latest drivers for Snow Leopard. This, however, requires you to update to 10.6.5, and use an appropriate boot loader with the following in com.apple.boot.plist:
More information can be found on insanelymac.