I was at the RV show here in Austin Tx last weekend and attended a seminar on maintenance for your RV here is a great link that has repair and maintenace tips. One of the items he covered was propane and the fact that in cold weather if the tank was over filled it just won't work correctly. Here's the link the ask the Professor was a guy name Terry who runs the RV Technicans program at the Tech school in Waco Tx.
http://www.everythingrvtv.com/
Hope this helps