Everything here worked perfectly. Although I submitted my code and then put my Pokemon to sleep... I guess it's sleeping now... but I can't do anything with the Pikachu C-Gear stuff. I clicked on the orange box and this window pops up and my only option is just to click "OK".
Okay, actually, disregard that. I left the site and came back and it had my Black sync'd up. I was able to get the C-Gear skin and I downloaded the Pokedex skin. After you enter that code and hit the DS ball, you can select what you want to download. When that's confirmed access the Dream World again on your C-Gear and wake your Pokemon up. After it wakes up the game will tell you what you downloaded.