Zippy, our friend. You may have nailed the problem. The pro check thing wasn't the problem, but I am glad I replaced it as it was bent.
The brass washer isn't there! I am not clear on how this may be causing undue pressure on the rubber seal. If the diameter of the brass washer is small enough that the baffle's feed neck, which is under spring pressure, seals against the washer and not the rubber seal, that would release an inordinate amount of pressure on the seal.
The instructions for installing the washer are at http://multiscalecharge.com/products_powderbaffle.php
The istallation instructions are to "Remove Rubber-Grommet from powder opening, just above the Bar and place our Brass Washer, with the sharp edge facing down, on top of Bar. Put back the Rubber-Grommet on top of Brass Washer.
• Screw Powder Baffle all the way in.
• Screw Powder bottle onto Powder Baffle.
I wonder if a common brass washer from Home Depot will fit. If not I can order on from Canada.