Just an update on this. We did send in the detector. I had to get rather insistent with the individual on the phone., He didn't want to have it returned and kept insisting it was sensing "something" in the trailer. Finally after almost 4 minutes of arguing with him I asked for a supervisor. At that point he agreed to give me a return authorization. They tested it and sent me a new one as the old one was sensing below normal threshold. So far after 3 nights it's still quiet.
I'm happy with the replacement, I'm just not happy I had to argue with the guy to get it checked.