X7 Phenom velocity screw air leak

I have a X7 Phenom and love/hate the marker. It's only a few months old and is becoming more a headache the longer I have it. The only way this marker will fire is if the velocity is all the way up. And even then the velocity never gets pass 280 fps. If I lower it even a little bit, air leaks from the velocity adjuster. I've cleaned, lubed, and replaced all o-rings. I can't seem to fix this issue. Tippmann wants me to mail it to them and they will look at it. I really don't want to go through that trouble of boxing, paying for shipping, then waiting for it to come back (and potentially have the same issue). Any ideas ?

Hi. I´m from La Rioja Argentina and i have a question. It is posible that a new guns come without an oring in the inner screw of the velocity regulator? it cames with a space betwen de male screw and the spring but no oring in there. I put a 17" oring, witch it´s fit perfectly, and the leak desapear. Is that posible?