Last week was the first time that it has rained since we bought our PUP. It was left out in the elements, and today when I opened it up I found that water had gotten in somehow. It was between the ceiling and the folded up canvas, but I can't seem to find where it came in at. Any tips on figuring out the source would be appreciated. The seals and caulking on the top all look good, but water got in somehow.