An old thread, but I believe I found the solution for the QD "evil corny" leak.
I struggled with a new keg which leaked from the QD, as described earlier in this thread. I changed the o-ring and lubed to the best of my ability, but the leak was still there. Then I tried to connect the gas to a keg which previously had not leaked, but now that keg was leaking as well, so my thought was that the QD was broken. But because the leak was not constant, and changed as I wiggled the QD, I tried ways of attaching the QD, yes, there are different ways of connecting the QD. It is a bit difficult to explain exactly the way to do it, but you want the QD to snap into place after you have pulled back the locking mechanism and lowered the QD onto the post just a bit. Do not press the QD all the way down before releasing the lock mechanism. And do not wiggle it. As far as I can tell, you want to do as little as possible, let the QD settle onto the o-ring by itself.
Hope this helps. It worked for me.