I am not entirely sure but I think it needs to be DDR2, not just regular DDR.
if i meant DDR2 i would have said DDR2, so as i said to begin with it he needs 2 sticks of 1 GB DDR ram,
source says it can run on 1.5 gb of DDR2, or 2 GB of DDR, and since his computer only supports DDR, then he needs 2 gb of DDR