Mine did the exact same thing. First time I aired it up, it was leaking. Does your leak get progressively worse? This is what I did..

Degas tank
Unscrew the front of the regulator w/ an allan wrench
Unscrew the next section (fairly big wrench)
In there is a little plastic cone shaped thingy with a spring on it
Mine was dry so I oiled it

Threw it all back together and it has worked since. I believe the issue was the front section of the reg was just dry. oil it all and see if this helps. Would also recommend buying an extra quick disconnect and a dye gauge. Mount the gauge on the QD. Makes it ez to see what you have in your tank. Of course if you are using macro this wont work