I've been using this co2 setup on a 20oz. paintball canister for about 4 months, and finally had to get a refill. When I reattached the canister and turned it back on, it started leaking a lot and the canister frosted over. It seemed to be leaking from the ASA on/off valve itself (couldn't tell if it was from where it screwed onto the canister or from the on/off knob), not the connections to the gauge or needle valve. What could be the problem? An overfilled canister? Bad o-ring?