Installed probe through the wall and ran auto tune for my SM1 last week. Today I smoked some spare ribs. Set Auber at 225, inside temp of box when I put meat in was 74 , the ribs were close to that and outside temperature was about 74 . Looked at it at about 1.5 hours into cook and noticed it was 230. At 2 hours it was at 225. I checked it periodically until the 3 hour mark, when it was still 225 and I took the ribs out to cover them with foil. Took about 3 minutes, temp dropped to about 175. It want back up to 230 then dropped to 220 before going up and holding at 225. Box dropped to about 180 when I opened it and removed foil. Now about 26 minutes into last hour, the temp is showing 230. Now its 36 minutes and it has dropped down to 222. At 40 minutes its down to 220. At 54 minutes its back to 230. Rose to 232 before ending up at 230 on the 60 minute mark when I took them out. Is this a normal fluctuation and the way it is suppossed to work? I have a feeling that I have done something wrong, but don't have a clue what it was. Any advice would be appreciated.