I recently bought a 256MB stick of PC133 RAM (since it's dirt cheap right now), and when I installed it, bringing my total to 512MB, I get crashes and low memory messages. When I back off to 384 I'm okay as long as my I/O voltage is up 0.1 (3.4V). Is it incompatible RAM? The two 128s are identical, but the 256 is a different brand. Why then would they work okay with just one and not with both installed? Thanks for the help!