I admit it--when it comes to external bobbin winders, I cheat. I lay a pen between the thread and the body of the machine, and if the bobbin isn't winding evenly, I guide the thread with the pen. Once the bobbin has a wrapper of mostly-balanced thread around its axis, normal distribution of the thread seems to take over. This hasn't led to the thread breaking on my (not your model) machine, so I'm not sure if the two problems are connected.
Kliban Qat
August 2009