Well I do now. But previously I had only BMD drivers. You think I should uninstall AJA to try 10.6.4? It crashes just the same as it did without AJA drivers installed. Really no reason they should conflict.
Why would that be "obviously?" I've actually never heard that. You can certainly have multiple GPU cards without their drivers interfering with each other. And FCP X supports a pulldown menu to choose the device you wish to use for output in it's playback settings.