I just got a 2012 Mac Mini and wanted to swap the ram between that and my 2008 uMBP. I have Crucial 2x4GB in the MBP and the Mini came with the stock 2x2GB. The 2x2GB works perfectly fine in the Mini, but when put into the MBP, the MBP does not boot. Both are DDR3 obviously, and I know the MBP is spec'd at a slower 1067mhz/PC3-8500 speed vs the Mac Mini at 1600mhz/PC3-12800, but memory should just clock down to the lower speed rating. I would expect stock Apple supplied RAM to be more compatible, if anything, rather than being not compatible between Apple products. Anything I'm missing here or is it simply not going to work?