I am not sure, but I don't believe my floor was glued down - I say that because when I walked in it was all bubbled and raised. In one spot I put my hand through the crack and onto the subfloor. Although it might have been glued and the glue just failed in the cold. I hope to get down there this weekend and get a better assessment (and some pics).
My neighbor bought a new 5er today, and mentioned to the dealer what happened to me - they seemed to think this could only happen if I had a leak. I originally thought the same, but I didn't see any signs of it on the subloor or elsewhere (and I had just recaulked the entire camper last summer).
Thanks for the the advice!