Make sure there is no "pull" of the weight of the remainder of the quilt Lisa. You need to have the full weight of the quilt supported. I pleat mine up all around the bit I'm working on. If you're doing straight lines, slow down a bit, the walking foot doesnt like going too fast!
Before I had a bigger sewing table I used to put the ironing board at the side of me and 2 chairs in front of the machine table to support it all.