Hello Wumba, Just wanted to ask you if the window cover you are talking about is the one in front of the window that is above the gas tanks 7 battery. If so, just want to let you know that we have a 2006 Rockwood 3817ss & we have never had problems with that window cover. We tend to use our trailer at least once a month, but unfortunately in the past year we had not used it at all. We went out last June & we just got back today from a 1 week trip. Even after sitting the trailer out for a full year (not covered) the window was perfect. Now on another note..I need to change it out since we broke it with a kayak that we placed on the bed of our truck. We took a right turn & the kayak was not placed in correctly into the bed of the truck & it tore up the fiberglass cover. So if you hapen to know of where I would be able to order that part, please let me know. Good luck in your new purchase.