Do you mean you are running the ram as pc 3200, 200Mhz ( 400Mhz). As far as I am aware 133Mhz ram cannot run at 200Mhz. Perhaps your motherboard is running a setting called SPD.
What is the make and model of your motherboard. Some motherboards do allow you to run a fast cpu but use a slower speed ram.
If you have managed to get the ram upto 200Mhz ( 400Mhz), then I think this will damage your ram.