I just recently upgraded my memory from 256 ddr 266mhzto 512 333mhz. I want just the 333 stick in but when running it i get loads of problems like windows wont load, coruppted files etc. So i was wondering if it could be somthing to do with my cpu being 266mhz fsb. Is this correct? I put the 266mhz stick in aswell and eveything seems fine when it's running at 266. Can anyone please help me????