Living in a cold climate makes one conscious of condensation. That poor frozen little Accu-Vote brought from 20F to probably 70+F would create all kinds of condensation on the circuit boards. That's why they put little packages of silica gel into some electronic devices for shipping and storage. Covered with moisture the circuit boards would either short out or cause erratic behavior. A cold Accu-Vote should be warmed up for 2 hours before being turned on. Twenty degrees F would not do good things for the life of the battery.
It sounds like the read head is suspect. I bet if you swapped the read head (for a proven one) it would work like a charm.
My two cents worth