Most people have the opposite issue. With infrequent use, slide outs are closed more than they are open. So, the exterior seal will stick and cause problems when trying to open the slide out after it has been in storage for a long time. Also, the exterior seal makes contact with the trailer wall but not the slide out wall, and the 'jump' will happen at the beginning of the motion.
From what you are describing, it sounds like the middle seal is not flipping when you initially open the slide out. Then when you try closing the slide, the seal finally flips. When wet, it never flips. If this is the case, waxing is not the solution.
Maybe look at my recent thread.
http://www.crossroadsowners.com/foru...html#post94856