Finally got to use my pitboss and I do not have the updated firmware, I did try using the grill set at 250 and it dropped to 225 and held solid there so I opened a case with pitboss and the response was as follows.
Hi there!
This controller has a proprietary PID (proportional � integral- derivative) based program. This program is based on a continual loop of feedback and algorithms that adjust and compensate to more accurately achieve and land on target temperatures. The program will gradually adjust the grill to reach a target to prevent the grill from spiking or overshooting temperature. In smoking temps (180-275), we have slowed down the jumps from set to set temp to prevent overshooting temperatures and better overall smoking experience. So, we recommend doing 2-3 "burn offs" at 350 for about 40 minutes each. This should help regulate the temperature.
The proper way to start it in order to maintain that temperature, you will want to start the grill up at 350 every time. Once it reaches that temperature, back it down to the lower (desired) temperature.
If this does not work. please let me know!!
From what I'm hearing pitboss is now just sending out new controllers don't even have to send the old one back. So even though I have my doubts about what they recommend helping I will try it and if not I will request a replacement controller.