My family just purchased a 2002.5 Coleman Yuma and are really excited to get out in the campsites this spring. This is our first popup and we were in the process of cleaning it when I discovered that a portion of the the rear left ceiling is wet and rotten behind the canvas track. There also appears to be some discoloration and possible rust on the metal corner pieces. My question is this: how does water get in between the roof top and the box? The seal between the two looks to be in okay condition... and what really throws me is that the water damage is above the seal, not below. Any thoughts or help would be much appreciated.