Shot in the dark, 'cause I've had a similar issue, but Pokemon Black and White use like three different ports to do trading, and if you don't have all three forwarded correctly, the game will be convinced that it can connect to Wi-Fi but then fail to actually use Wi-Fi.
If that's the case, then there's no way I can fix it because I am using campus wi-fi, not my own router, so I can't control the port forwarding in any way except from my DS.
I got Black 2 as a continuation of my "Nuzlocke Run All the Games (Gen 3 and forward)" plan. I am currently on game 2, Heartgold. Once I finish Black (which is the game I'm using for this run), I'll move on to Black 2.
Last edited by tgva8889; 2012-10-09 at 11:49 AM.
Thanks to araveugnitsuga for my current Poke-atar.