Cotrol surface "Jumpy?"
Try a 4.8V pack just to see if the jumpiness goes away. If it doesnt, I'd look at the linkages, surfaces, connectors, hinges again.
Regulators......
I run Powerflite Li-Ions in my 33% Cap and they are 7.2V Batts
The regulators take them down to 5.7V
I usually see close to 8V after a charge.