Ya your should have the probe in the middle of the incubator. Think of it like the flexwatt is heating the air, so you want the probe to sample the air. If you were to put the probe on the flexwatt you would get a very accurate temp on the flexwatt but not the air. Also try to setup the fans so they work togeather to move the air around. like you are trying to push air around an oval track if that makes any sense.