I can tell you that the pork butt time seems to be right on. My somokette when set at 225 will take 2.5 hrs per lb for pork butts. Usually I do 7 to 8 lb butts and they take16 to 18 hrs to reach an interal temp of 195. I put them on in the evening and take them out the following day when the remote therm. beeps at me. I have done baby back ribs and they were done at 6 hrs.
Make sure if you are using an extention cord that it has good ends and is at least 14 guage. It could be the house voltage in your area is only around 110 volts instead of a full 120. check to make sure the outlet you are using is in good condition. In other words the cord should plug in and be very snug. feel the cord end and make sure that it is not warm at all to the touch if it is this could be part of your problem. but your times seem within reason to me. I would expect the ribs to be done at by 6 hrs though.