I have a Destination 39W/mate to yours and would suggest you check the main TV to see if it has tilted or dropped on the wall side. You may be experiencing expansion and contraction noises as a result of the problem I found a couple of years ago when I realised that the shelf/counter top that the TV sits on is not fastened to the exterior wall, just behind the left sildeout. The original TV weighs 117 lbs! You can check by opening the drop down cabinet door below the TV and looking up at the bottom of the TV shelf. If you do a search on the Winnebago site here, you can find my suggestions to fix this.
As far as contacting the customer assitance people at Winnebago, I have had great help from Rod. Try asking for him. He is knowledgeable and efficient.
08 Destination 39W
09 HHR SS in tow