Did Duke Energy Lower November's GCA Natural Gas Rates Too Low?

November's GCA was lowered and then December's GCA was raised this week.  What goes?  With the spot market hovering in the $3 - $4 range for the year, and the futures for December, January and February in the $4 range, and the economy down, why doesn't Duke Energy's GCA reflect some of these low rates as it should? 

The reduction for November was seemingly sound.  The increase for December doesn't seem so.