I've gone to the local co op, got the deraileur hanger fixed. I noticed something else, on the tension pulley wheel, one of the teeth has completely broken off. Is that of any concern? I also had a bent front chain tooth, the guy in the shop tried to bent it back and ended up breaking it off, well 1/2 of it. First he tried to hammer it in place (which I didn't understand how that was going to work since there is no support). This is why I always want to learn to fix my own stuff.