On my US 60 this happened as well as the leading edge of the wing. I think one of the problems is that the wing does not really have a good snug fit. I solved my problems in several ways. Not only did I cover the mounting dowels with pieces of aluminum arrow shafts but I also lined the wing saddle with, 1st contact cement and rubber bands (lasted a little while), 2nd I picked up some door insulation strips from Lowe's and lined the wing saddle with that. Finally, I also placed a little insulation between the wing mount holes and the leading edge of the wing. I haven't had any more problems.