Anyone know what DD#2 stands for on the back of the topcase? This follows the product number (e.g. 613-xxxx).

I ask because I bought a topcase that was supposed to be compatible with my 1.83 Core Duo MB and I have a feeling that this might not be totally compatible with my chip set. Any thoughts appreciated.

Incidentally, my original topcase p/n is 613-6408. the new one is 613-6695DD#2.