I have an early 2008 mbp but i've had the battery, logic board, superdrive, and screen replaced so far. battery wouldnt hold a charge, was defective. the screen was doing weird backlighting things so i got that replaced, the 8600m was scrambling graphics so i got a new logic board, and the superdrive wouldnt burn dl's so i got that replaced too. now the hd sounds like its on its way out (louder, more ball spinning for no reason on SL), and i've still had a few scrambled graphic screens from time to time (another defective 8600M?) should i demand a replacement computer? where from if so? retailer/customer service? halp?