Reprograming the SPD (On ram chips)

I have a CAS 3 chip that runs perfectly at CAS 2, i put it in a different motherboard and set it to CAS 2 in the bios. At bootup it detects the SPD is saying CAS 3 and gives me an error saying my ram is setup incorectly in the bios. If i set it as CAS 3 in the bios it will boot up fine.

I know the ram works fine at CAS 2.... so how do i reprogram the SPD chip to report to the bios that it is a CAS 2 chip?

I'm sure it's not a very hard thing to do... can anyone tell me how/know of a program that will do it?

Thanks