Definately let us know how you make out with that. I was wondering if the aspen had something to do with it but I doubt it since the bottom two are spot on. Mine has been like this since I plugged it in.
I was having the same issue with my ambient room temps dropping since it has gotten chilly here at night. I went to Home depot and bought a small electric oil heater for about 35 bucks and my snake room is nice and toasty. My cold side reads 82-83 since I bought the space heater. If I had to do it over again I would have spent a little more money and bought a space heater with a thermostat already on it, mine only has low, med, and high with a number dial to set the temp.