I have a new 2014 Grey Wolf 26BH with a Model 300 Dometic toilet with the same problem. Our dealer here in Ontario quickly replaced it with another Model 300 and after 3 days of use, we had the same smell issue. I found all these similar posts here in the FR Forum and let him know. He never heard of the problem, and is sending me a new Model 310 ASAP. The Dometic distributer in Brantford said they are also unaware, although the Dometic Rep in the previous posts in the US, is very aware. I don't understand why FR is not demanding Dometic to re-call these units?