I want to upgrade an early '08 MacbookPro and am seeing conflicting information from various sources. Crucial website says 4GB RAM is max. I have also seen 6GB given as max. The system currently has 4GB and with 2 slots so I would need a 4GB module. Does anyone know definitively if this system can access 6GB? The machine will be for light duty work; web browsing, email, light graphics for web maintenance, word processor, etc. The reason I want to upgrade is just so I can upgrade 10.7.5 to latest (or more recent) OS. It's running 10.7.5 fairly well, if a tad slowly. Thoughts on whether this is a good investment which will extend useful life of machine?