I have seen alot of topics and discussions about this but no one have made an easy explanation how to solve this! Therefore... I'm doing it! Ok, THE PROBLEM: You have an wireless router and you can access internet with your Wii (Shop channel, Everybody votes etc. works fine) you can also access Nintendo WFC, BUT when your Wii are searching for others players (Mario Kart Wii WFC for example) it dosent find any and then all of a sudden "Error code: 86420" comes up... and says: Connection broken (or something) what to do... THE SOLUTION: In the wireless router TURN OFF "SPI Mode" in the firewall settings! ...simple... ANALYSIS: Because the SPI scans every package recieved through the router and since it's task is to remove "Internet Background Noise", turning this mode OFF allowes the WFC data to be treated correctly and not like "Background Noice" (causing the 86420 error). Works on Mario Kart Wii WFC, should work on SSBB also but since I live in Europe I don't have that game yet... Last, a word of caution: If you don't know anything about routers you should really consider asking someone to help you. Ok, let me now if this has helped you... (I wanna beat some n00bs om Mario Kart) Peace!