Dusty,
There are three things that come to mind right away:
1 - Are you sure of the amount of LP in the tanks.
Weighing the tank is the best way to confirm this.
2 - Modern regulators have a system that shuts off the flow if it higher than it is should be. This can happen with just opening the tank valve too fast.
Close the tank valve and wait (I am not sure how long) and then open the valve very slowly.
3 - The regulator may be out of adjustment or have failed.
Either build a manometer or get someone (Like an LP service) to check that the line pressure is 11'WC.
Matt