I just completed my first cook on my new 590, it was a success, even my wife really liked it, and she does not eat much meat1(she went back for seconds) The problem is the grill went way over temp. I first cooked for 1 hour on extreme smoke, then kicked it up to 250 for an hour. Temps stayed perfect. Then to crisp up the chicken, bumped up to 365, temps were steady for 15 minutes, then they climbed to 397, then it stabilize there. It was fine as I wanted a crisp skin anyway, but I do not want it to climb when I am doing low and slow obviously. Everything looked fine inside the grill, temp sensor where it should be, not bent, etc. No grease fire, everything looked normal, but temp started to go a bit crazy. Anyone have any ideas before I call H.Q.? Maybe it was just a freak thing and I should try my beef ribs or brisket and monitor it closely. Don't want to ruin those, they are expensive!