this may seem like a silly question, but I just wanted to check with the experts! i recently purchased a 15" macbook pro on ebay, advertised as the 'NVIDIA GeForce 9400M + 9600M GT with 256MB' model. so when i opened up system profiler to check the specs, under graphics/displays i see 2 video cards: Chipset Model: NVIDIA GeForce 9400M Type: Display Bus: PCI VRAM (Total): 256 MB and Chipset Model: NVIDIA GeForce 9600M GT Type: Display Bus: PCIe PCIe Lane Width: x16 VRAM (Total): 512 MB so my question is this: is this (as it looks) the +512mb graphics option or the +256mb option? i'm confused did i get more than i paid for? i hope so!