I was reading that the MBP can take more than 4 gb ram. Is this true? I have a 2007 SR MBP with 4 gb ram. Is it possible to put in 4 gb module and a 2 gb module to make 6 gb, or maybe 2 x 4 gb modules to make 8 gb? If this is possible, will Snow Leopard improve the ability of the computer to use more ram or more cores? Thanks for any advice.