I have an ECS P4M800PRO-M(V2.0), Pentium D 915 OC to 3.2GHz, 2GB PC2-5300, and I am running Windows XP Pro. My board supports up to 2gb of PC2-4200(533MHz) and that is what I ordered on Ebay but I received 2GB PC2-5300 instead. I'm not complaining except my board only reads 1GB PC2-4200. I know the speed is backwards compatible, but I do not understand why the BIOS only reads 1GB. DX Diagnostic Tool, PC Wizard 2008, and CPUID all read 2x1GB PC2-5300, but the BIOS does not. Can anyone explain this to me.