Okay all just wanted to report back that it is all operator learning on my treadle. After a week of sewing a little every day I am doing much better. I think it was all a bit of foot placement on the pedal and the stiff new belt that was slipping.
I don't break the thread that much anymore but it is usually when I am slowing down and then start up again. I hope to post some pictures tonight but have a virus again on my computer I think.
Thanks for the sweets.