Abit nf7-s problem please help

I have a problem with my nf7-s if I try to insert a stick of pc 3200 from twinmos the mobo sees it as pc 2100. I’ve read the manual and tried every thing but it won’t recognise it.
What should I do? There’s nothing wrong with the memory cause I already changed it for another one with the same problem.

Did you go into the BIOS settings for your mobo and make sure they are set correctly for that speed of ram? Is it by SPD? Or depending on whether or not your OC'ing, is your FSB set to run at 200MHZ?, which is PC3200 speeds. Give a little more info on your settings to better help you out.