Also, when you first air it up it's normal for it to leak. You need to fire it at least once to latch the hammer on the carrier, otherwise the spring pressure holds the valve open.
Taking it apart like Marty said for testing is also a great idea, makes it much easier to figure out exactly what's causing you problems. I forgot about it since mine have actually stayed working for a long time
Marty's mods are the main reason for that.
Quick question for you, the only problem I have now is every few cases the bolt link will snap. My bodies are a bit worn out from the bolt link, would adding a set screw to the carrier help much or should I just stock up on bolt links?