I don't mean to add insult to injury, but having done the same thing I make it a rule to always thread bottom bracket cups by hand (at least the first 1/2"); it will save you the grief you are going through.
A for your problem, did you strip the threads on the cup or inside the BB shell?
If you are replacing an old bottom bracket, and the damaged threads are in the shell, you may be able to chase the threads with the old cup.
Last edited by onespeedbiker; 09-16-12 at 09:03 PM.