I'm guessing the leak is a separate issue, but the not firing may be the same problem I had. When you pulled the trigger you could hear some air, like it was trying to fire, but no bolt movement.
In the Flex-valve, there are inner and outer spring clips that hold the end part of the valve that the bolt rides on. The outer clip is visible, the inner one is not until you remove the outer one and the end of the valve. The inner clip on mine broke, and a small piece of it was loose inside, jamming up the flex valve. I removed the loose piece and it worked for a while till I guess more of the clip broke off. You can read my whole story here...http://www.x7og.net/phenom-tech-help...-know-how.html
X7OG is a great site if you own a Phenom.
The outer clip was a real PITA to get off, even harder to get back on. I didn't even try the inner one. I sent it back to Tippmann. The parts I am talking about are #5 in this drawing