After about 10 sessions of smoking meat I had one go bad on me. I had ribs that I don't think were burnt, I think I actually acumulated creosote on them. This is the first time I made a strong effort to keep the smoke going. The ribs were in the top of the smoker and I had a pork but on the level below that didn't get blackened anywhere near the level of the ribs? Is it likely I had this happen? I don't have vents at the top of my smoker, it's about time I change that though.