memory

I recently picked up an extra 512mb of RAM to bring my total up to 1.5 gigs. I have 3 sticks (maxing out my slots). When I installed them and then tried to run Guild Wars, it said that the memory timing is exceeding what it was meant to and I need to lower my timing. Question is, where do I do this in my bios, and how low do I set it when I get there. I have an Asus A7V8X-X (6 PCI, 1 AGP, 3 DDR DIMM, Audio, LAN) with 3 PC3200 sticks of memory. Any help would be great. Thx. Everything else runs great on my system. I just reformatted and reinstalled windows. I installed everest and this is what it gives for speeds:
200mhz 3.0-3-3-8
166mhz 2.5-3-3-7
133mhz 2.0-2-2-6
The numbers are the same for all three sticks.