Very, very curious: Other World Computing (OWC) discovered, somewhat "unintentionally", that MacBooks and MacBooks Pro 2008 (still with Intel Core 2 Duo chips) received "recently" new versions of firmware / Boot ROM that make it possible to work with up to 8GB of RAM. The previous limit was 6GB.
To access the ?benefit?, all machines must have Mac OS X 10.6.6 Snow Leopard or higher installed. MacBooks must have the Boot ROM MB51.007D.B03 installed, while MacBooks Pro use MBP51.007E.B05.
The EFI Firmware Update that enabled the extra memory capacity had originally been reported to affect only the SuperDrive on these laptops. Apple stuff