Dressmaker 700 won't feed
 

I was going to use the Dressmaker's fancy ZZ stitches for a project last weekend but I could not get the material to feed fast enough. I ended up with a super-tight satin stitch on my piece of test applique. The stitch length was set to 2 and I made sure the button-hole stitches weren't engaged. Without fabric and with the foot up, the feed dogs worked in all three positions (up, middle, down) but once fabric was in I couldn't get the feed to go at all. Any ideas?

How thick is the thread? Is the stitching able to fit under the presser foot? Is it a slippery fabric? Does straight stitching with the same fabric work okay?

Once when my friend had that problem, we took the whole thing apart underneath and found a bunch of lint clogging up the feed dogs. It appeared to work until she put fabric in it to sew.