I bought a 512 memory module for my G4. When I installed it, system profiler keeps saying it's 256. I have a 128 and 2 64's in there. In the 4th slot I put the 512. I tried just putting it in (to make just 512) and it still said. What is weird is that when it only had the 512 stick in there, it seemed faster then with just the other 3 sticks. Is it just saying the wrong number?