The times described for the ribs/butt are beyond the norm, so you may have a controller issue. Do you have a remote therm that can be used to check the box temp? If so, try an other run with the therm in the box and set you temp for say 225F...you should see temp swings +-15F or so from your set point. If you don't get to 225, then try ramping up the temp on the smoker to 250F and see what temps you get. This may be as simple as adjusting the temp dial, or worse case the controller is bad.