Odd, we've had ours for many years and aside from a bit of a dip between the two sides we don't have motion or foam issues like that. This is my second (I had a small one when I was single) and I've disassembled and reassembled them a number of times in the last ten years... I could look at it and maybe fix? I'd have to say the biggest issue for us, air holding aside, is I keep my side super firm and he likes his super soft so if we try to come together in the middle hilarity and/or frustration can easily ensue.

FYI, if you end up with a Revere Ware pot/skillet at a garage sale or resale shop you can get a matching lid at a Corning outlet :)