Memory Problem??

Ok, here is my (possible) problem. I have an older computer with a motherboard that noone has heard of (AZZA p4x4-alh). The manual says the fastest memory speed it can go is pc2700. Up until yesterday i was using 1.25gb of pc2100. I just bought 3 sticks of memory from circuit city that are pc3200, but can run at pc2100 or pc2700 as well.. But, here is my question... When i was running my pc2100 memory, at boot up the memory test showed 1.25gb of ddr266... now its reading 1.5gb of ddr400.. isnt that equivalent to pc3200? shouldnt it read ddr333?? so, is it running too fast and too hot? should i be worried? could it be that the manual i have is from before pc3200 was out so it was up to date? even the info online (what i can find) says up to pc2700.. thanks for the help in advance!!