Over the past year I have noticed the gel coat on the entertainment slide of my 2007 Bighorn is turning a noticeable yellowish color. The trim around the outer edges of the slide is still white as is the metal skirting on the bottom. The rest of the gel coat on the trailer and other two slides seems to be OK or at least not as noticeable. The trailer is washed and waxed regularly and is moved frequently so excessive sun exposure on any one side is not an issue. I just stripped all the old wax off and applied a new coat, but the yellow is still there. My guess is it ain't coming off. Anyone else experience this problem?