I am an art quilter that purchased a 440 about 9 months ago because I wanted the BSR. I'm having a real problem using the invisible and metallic thread with the BSR - the thread breaks. When I asked the dealer about it, I was told the interior of the Berninas get very warm because the gears are all metal. The metal heats up, the thread stretches and then breaks. She suggested I take frequent breaks if I want to use the invisible or metallic thread so the machine can cool down. Is anyone else having this issue? I used the Sulky invisible and metallic thread almost exclusively on my Janome with no problems. This is very frustrating. Any help would really be appreciated.