I loaded up Easytune on my comp just to see...
It reported my RAM as running at 200MHz, as it should since it is DDR. I think with your comp, it is reporting it as half of your FSB for some reason.
and check your RAM speed from that. That will give you a better look at what speed everything is running at. If you find discrepancies with CPU-Z that you are unsure of, post screenshots of the CPU-Z windows