If the paint is too thick it can scale. It is really hard to tell from a photo. When I am firing my black trace lines I put the glass in a cold kiln, ramp it to 1225, crash it to around 700/800 crack the lid and call it a day. With the quick fire kiln, in my studio, the glass is in and out in around an hour. I don't think you need a complicated program to fire the glass, more than likely it is something in the paint or there was something on the glass, uneven paint, paint too thick.....sorry to not have a better answer or a quick fix. Unfortunately, these things can pop up out of nowhere! When I am doing an important piece that can have no imperfect areas I often to two or three at a time in case something happens, that way if I am several layers/firings in I am not all the way back to square one.