My primary OS is osx86 10.5.6
I can see it's x86 so 32bit, but just what does 10.5.6 mean? I assume that it's a Windows 7 build since you're here @ Windows 7 forums but there's no 10.5.6.
I take it that since it's an Asus board, you have an Award
BIOS, version 2801
That version fully supports the quad core so that shouldn't be the prob...lemme check on that error code.