Currently Being ModeratedJul 14, 2011 8:58 AM (in response to RBC03)
People have tried to force XP and even bought retail 10.6.3 DVD, the last DVD there is and some drivers but nothing 'tuned' for your motherboard and chipset and drivers.
A VM is one way to run XP.
Install Windows 7 is only supported. Vista SP1 support has been dropped by MS already also.