Golf V R32 :: Internal Flap Is Stuck In Open Position?

I dyno'd my car a couple of weeks ago and we found that the torque curve was a trough instead of a bump compared to stock - down about 10. HP was down maybe 5 (I don't have the printout in front of me). Magically, at 4100 rpm, it crossed over the stock curve and then was + 10-15 HP above stock, as you would expect from tune, intake, and exhaust. So it seemed that the power port vacuum valve was not activating. We did not have time to diagnose, so I went home and T-d in a vacuum gauge under the actuator.

From the info. I have been able to find, the flap in the manifold closes at 900 so that just the long runner torque pipes are open to the valves. And then it opens to the tuned closed port at 4100 rpm. On a cold start, there is a brief period when vacuum appears on the gauge, then it goes away and does not come back regardless of the engine revs. So, given the low torque curve below 4100, I am wondering if for some reason the internal flap is stuck in the open position.

What else I should be looking at? For instance, at idle, the flap should be open. Does this mean that the little white plastic lever is pulled down, or pushed up? If the valve is active, there should be vacuum under the actuator, right? Any way to tell if the solenoid is getting a signal from the ECU to activate it?