I have a laptop running XP because of the high memory useage of Vista 64. I cannot find any info anywhere that I can use 2 x 2gb DDR2 modules in place of the 2 x 1gb that came pre-installed. Sony says on their website the maximum is 2gb - but Intel say the chipset (GM965) can use more. Does anyone know for sure that 2 x 2gb will work ?