Need Some Help With My A5

After cleaning my A5 it just leaks air right out of the barrel.  I have cleaned and oiled before and never had this problem.  All of the o rings look good and i have checked to make sure that i have reassembled it properly.  And it still leaks air.  Does anyone know of a possible cause for this, any suggestions would be appreciated.

Im actually having the same trouble with my own A-5. How do I fix it. I looked at the parts list off of Tippmann's and everything is in order. Still doing it though. Is there a certain position that the o-ring needs to be in. I set it right on top of the washer but it won't let the Tomb adapter into the tube. I also thought I found a area up farther close the the exit of it and stuck it in there and it set in very well but it is still rapid firing even before I set it up to fire. 

The same thing happened to my A-5. The tricky part is fitting the o ring down on top of the washer, far enough so the tombstone adapter will still fit. There should be two set of grooves in the valve, with the spring and bolt furthest down, the washer in the next groove, and the o ring fitting smuggly in the final groove.