UPDATE: Went to my local HBS to swap the QD out-the first new one they pulled out had the same problem- so I am sure there are a bunch of these defective QD's out there.
It's very simple to catch, just unscrew the top off the QD and take the guts out and shove a probe through the side...
Freakin AWSOME!
After 3 weeks of searching and drinking flat foamy beer. This post solved my problem in 5min. The key is actually where the carbonation was “coming out of solution”- at the QD. Took my brand new QD apart and sure enough- the hole is obstructed. Swapped it out with...