If you haven't already done this:
1. Confirm that the forms are mis-aligned with a string stretched along the keel center-line. Line of site on a large boat when you're just a few feet away can be deceiving.
2. Make sure that the strips progress up the hull the SAME distance on each side
3. Make sure that the sheerlines are parallel, one side to the other. Using a small level can help you do this.