Your first coil definitely was meant for disaster. Micro coils with Ni200 have to be perfect or they'll hot leg, which will do just what you described. Your second coil, the standard (spaced) coil is the way to go however you still had problems with it. Make sure when you do a standard coil that the wraps are spaced far enough that there is absolutely no way for them to shift and touch during wicking. It sounds like a hot leg problem to me or a short in the coil (something touching). Build a good spaced coil and fire it in temp mode without cotton. Pulse it at a low temp like 350*. You'll know right away if it's a hot leg issue.
