So my mum uses a 2009 15" 2.4ghz 2 Core Duo MPB with 2 GBs RAM. I use a 2010 13" 2.4ghz 2 Core Duo with 4 GBs RAM. Her laptop runs silky smooth on Lion, opening apps faster, even the graphics such as minimizing a window or moving to launchpad are more slick, while mine feels sluggish. Its frustrating the hell out of me! I have two partitions, one SL and one Lion, and both are slower than my mum's, even though she has 2GBs RAM! Any suggestions?