It has to be tightened very tight.
Just like any "Boston Valve" type valve.
I remember having to crank down my Cabrinha's '04 ish
or they would leak also.
Unlike the old valves, the Ozone wont twins the baldder inside the kite.
Crank the bitch down, no problem..
Lots of pictures here http://tinyurl.com/no9j8f2
(of course cranking it down, can mean more to some than to others, tight is tight)