When the silver version was released it had firmware ver 2 which was never released for the Black. So at release it could do more than the Black version.
On the 18th firmware version 3 was released which added more features to both cameras and made them equal apart from colour.
Yep thats it,i think a lot people got confused because the Graphite one also had some firmware released on the 18th,not just the black one,when they first gave all the specs for the Graphite one,they did say some the feature would come out in an firmware release after launch.