What could be the problem of my Union Room conection?

Question

I know this question is against the rules but I'm getting a little desperate. I have two Nintendo Ds. One is the first model of DS and the other one is a Nintendo DSi.

I enter the Union Room with my Black 2 in the Nintendo DSi and with my SS in the Nintendo DS. Here comes the problem: I don't see each other player, that must mean that they aren't connecting with each other.

The question is: What could be the problem? (With the solution if possible).

Thank you very much in advance.

Answer 1

You cant trade between 4th and 5th generation games. You cannot trade anything from B2 to SS but if you want to transfer Pokemon from SS to B2 just go to the Pokemon transfer lab on route 15
Source: http://bulbapedia.bulbagarden.net/wiki/Pokemon_Transfer_Lab