I must concur with kijana -we had a Winnebago Rialta a couple of years back- when we went to bed the alarm suddenly went off in the middle of the night. After much investigation nothing was found to be amiss so we settled down again.After another short period it went off again! the only thing that had happened was that I had farted!. This I think proves the link and also shows how sensitive the detector was. Mind you it was fitted near the floor on the kitchen unit. So beware- it might happen to you!!
Sweet Dreams

Dave& Jen