Pokemon: HG/SS "Communication Error"

Hey Guys...
I own a legit of HG & SS Version.
Now...I want to trade some Pokemons from my Flashcard SoulSilver. Everytime it say sth. from "Communication Error."
Last time I was able to trade, but now... :-(
What's the problem?Greets, Chris

No-one had this Problem so far?

well I dont know where the problem is...Did you try to turn both DS on and off and try it again? If you have a DSi check that the WiFi is turned on...