SwedeAce , I had this same problem with my Something Extra. I laminated 1/16" balsa to the wing rib at the low areas only. I then blended in the new balsa until it was flat and true with the rib and the fuselage. I hope I wrote that in a way that makes sense. I have been flying this plane for about 3 years and haven't had any problems. It is a great flying airplane. Good luck.