I just started working with leather and or some reason, the bobbin thread is not getting picked up by the spool thread. I am using a Euro Pro 7130 machine. It works fine with every material other than leather. I've tried increasing/decreasing the tension, increasing/decreasing the stitch length/width AND I've tried fixing the timing but nothing is working! Does anyone have any advice, tips or tricks? Oh, I just wanted to add that I've sewn leather before with this machine a month ago and it worked fine. Just now it's not.