Question regarding DDR SD RAM ?

I"m using P-IV WIth the motherboard of Gigabyte GA-8VM533 (Available with 2 DIMM slots supporting up to 2GB of DDR266/DDR200 memory, GA-8VM533 provides the highest performance platform with the highest bandwidth (2.1GB/s) mainstream DDR memory solution) as per their Website. I have placed PC3200 DDR SD RAM Of 256MB but I'm not getting any display. Can anyone tell me the difference between DDR266/200 and PC3200? Is it not compatible wih my system, or I have some other problem ? Pls Help