I had this problem when i changed my origin name. I was hoping it would change my forum name but it didnt (unless im doing something wrong). When i loaded my game after name changing it warned me about how my game hadn't been saved and some other warnings about beware your game will reset, sorry i cannot remember the exact warnings. So i just clicked ok, well wasnt really anything else i could do, the game loaded and as i feared a reset, my original town loaded up. Thankgod for that, origin id stayed the same as the one i changed it too and luckily my town remained.
