I stored my LSS for about six months in a heated and air conditioned room. When I removed the cover on the LSS yesterday, I found a large bubble which was stuck to the inside of the Mesa cover. There are smaller bubbles also. I've never seen this happen to an amp's tolex . I've had the amp since 2005, but bought this head shell from Mesa about 8 years ago to make the amp easier to transport. Any idea what would cause this and what a fix might be?