I haven't had any trouble with mine, and have been flying it about a year and a half. The heads on your bolts are probably stripping because running in 1" of bolt into a small inconvenient area is irritating! Did yours actually call for 1" 4-40s at this location? Anyway, i use 1/2 inch. One thing you can do, is go ahead and put your 4-40s in from the top of the mounting bracket, use 4-40 standard nuts, with locktite directly on the other side of the mount and make them TIGHT. When you assemble the cub wings, you can slip the strut fittings over the remaining thread on the 4-40s, then nut them on with a small nut driver, and never have to touch the head of the 4-40 allen head... I don't do this on the cub because I haven't had any problems, but I have done it on others.

Chad