I have the Mid 2010 MacBook, it seems to support 16gb of ram just fine since im on Mountain Lion and have the latest EFI update i believe. I get the single beep code with pauses in between. Its 1333mhz, And i thought that would work fine. It seems to work fine with just one stick of 8gb and then the standard 1gb 1066mhz stick, giving me 9gb of ram. But i would like to have the full 16gb. Anything i can try?