Gotta crack?
 

Pretty common thing I've seen are cracks in the rock shield covering the front window (and a few other places). A boat repairman also sees this type of cracking throughout the his industry. Cure for him - Q-Bond. he told me how to use it and I followed his instructions and then clamped the affected area, low and behold, it worked! Be it known though, it won't work on everything, like PVC, but it's worth trying it. Two kits for 20 bucks on amazon. :)
Tree
P.S. New rubber on the Treehouse. Maxxis 8008's LR D, mounted on balanced rims. Peace of mind - priceless!