you must be running amd which ram clocks are now sycned with the cpu not the fsb.
also since your running ddr2 its dual pumped so multiply that by 2 and your ram is running at ddr2 737. so it is ddr2 800. a slight oc might fix that but probably would just confuse you so get ddr2 800 and you wont have any slow downs from the new sticks