I'm wondering if the feed dogs are moving the top/bottom fabrics differently. Perhaps as stated above, your presser foot is too heavy. A solution may be to start sewing approx. 1/2 inch down the piece, then reverse to the beginning of the fabric piece, then going forward to finish sewing the piece, so you are not starting on the edge of the fabric.
Also, since it seems to just be the red fabric, perhaps it maybe a little off on measurements.