I have a pretty good Blackburn(older model forget #) Its all aluminum with a cast Al base, nice and solid with a good guage, but the air chuck gives me the same issues as yours, the weight of the hose and the air chuck twists the chuck on the presta valve and makes it a pain in the butt. I use a presta/schrader adapter and the wider diameter of the schrader seems to cure the problem.(the air chuck does both types)
They sell nice metal air chucks that I may get at some point.