DS's won't connect to each other

[deoxysdude94]

2 hours ago, I connected my pokemon soul silver(which I have all 16 badges in) to my pearl version (with one badge), and they saw each other in the union room. I try to connect now, but they can't see each other. What possible explanations are there?

[dragonskull]

I think you need to get the national dex on pearl first, since you can trade alot of pokémon which you can't obtain in pearl before the national dex.