Hi there, Can anyone give me advice on DDR memory compatibility with my ASUS P4P800S-X motherboard please? I currently have 1 GB of PC2100 266mhz memory in my system but I want to upgrade. I can only afford a stick of 1GB Kingston DDR400 PC3200 serial number KVR400X64C3A/1G which (I hope) will work on its own in this mobo. I want to know if I could mix the 2 sorts of memory (DDR400 & 266Mhz) to give me 1.5 GB of memory. Next month i will buy another 1GB stick and replace the 512MB PC2100 so this is only a short -term problem. Thanks for the advice.