I have a Janome 6600, and have had a wonderful time with her since buying her over a year ago. Now...all of a sudden....I can't get the tension right on the backside of the quilt while fmq. I've tried rethreading (Connecting Threads cotton, top and bottom), new needle, cleaned out the bobbin case, tension dial at all points. Nothing is working. I still end up with the thread laying on the top of the backside fabric and dots of the top thread very visible. I am frustrated beyond belief. I've tried to set the speed at high, low and somewhere in between with no difference. I've tried going real slow with the fabric and all I end up with is very small stitches and the same issues on the backside. Somebody....PLEASE....tell me what I am missing? Is it something simple? Or is it time for some basic maintenance?