So I am thinking about building a new PC for myself ( I am still in the "buying hardware" phase), and I have a question concerning RAM. I am planning on buying the ASUS A8N-SLI Socket 939 mobo, with twin sticks of Rosewill 1Gb RAM. However I notice that there are two different versions of these, the Rosewill 1GB 184-Pin DDR SDRAM DDR 400 (PC 3200), and Rosewill 1GB 240-Pin DDR2 SDRAM DDR2 533 (PC2 4200). Which one is compatible with the mobo, and if both are, which one should I choose? Keep in mind that I will be buying twin sticks, to bring my total RAM up to 2 gigs. This will be the first computer I have built on my own. I will be primarily focusing on online gaming, audio, and web-browsing. Thanks in advance!