Here's my temporary solution that just might become a permanent solution!

The idea of reinforcing the 'bird with zip ties inspiried me to try to use them to fix this problem as well. I pulled the broken plastic peg out and ran a zip tie through the hole. I slipped three rubber bands through each side, then tightened it down (but not too tight). This should hold the bands in place. In a crash, the wing can still seperate by releasing the bands on the front mounting point. As a bonus, no more lost rubber bands! (I've already lost two.) I've attached some pictures, and I'll update this after flying a few more times to let you all know how well this method works.