I have an early 08 penryn MBP. I went from 2GB stock ram, to 4GB G.skill 4-4-4-12 ddr2 667 RAM. Now vista x64 is slower and is hanging a lot more. This is happening via parallels AND Bootcamp. Parallels is unbearable. I'm using Parallels 4.0. Has anyone experienced anything like this? I am going to be getting a 320GB 7200rpm WD Scorpio hard drive installed in the next few weeks so a fresh install of everything may help... but I'm wondering if I have defective RAM?