From: Epitaph of Darkness | #009 ...Why in gods name did it give me one of the ****ing preschooler avatars is beyond me. Of 'all' the things a player should have been able to customize, THIS SHOULD NOT HAVE BEEN COMPLETELY RANDOM.
It's not, everyone gets that until they change it.
Currently playing: Pokemon White, Dragon Age: Origins, Tiny Wings PSN/Gamer-tag: JimCamX FC (White) 3482 2095 8227
No, you're Game Synch ID is locked to the save file on the cartridge. The only way to reset it would be to erase the save file. (I don't recall ever having my Friend Code reset when switching DS's either... only my Pal Pad's list. Hm.)
Unfortunately, since it appears that once you register a game save's ID to the PGL, it's impossible to delete, so if you did reset, you'd be effectively blocking yourself out of your own account. (the only way to really use it again would be to get the other version and connect it and never reset that one, or to forget about your old account and just make a new one. I bet you'd even have to make a new Daisuki Club/Pokemon.com/[whatever the other languages call it] account on top of THAT though, so you'd also lose everything related to the old acount, like your Daisuki Coins, Avatar Items, etc.)
I have to say, I really do hope an efficient method is either found or supplied to fix this difficulty... Especially in the (unlikely) case that someone's cartridge got damaged or something, cause that would really stink. (not that I'd think GameFreak or Nintendo should help that person re-obtain any Pokemon they lost or whatever; it's still just a game.
Hm, has it been confirmed that this applies even if you have both games' IDs registered?
Your friend code doesn't change just from booting the game on a different DS, it only changes when you try to connect it to the Internet on a different DS. I don't know how this works with game sync though.