Has anyone ever had a problem with a rear dump valve on an aqualung bc? My axiom i3 has a problem with the rear "flat" dump valve. It holds air medium well, but emits a slow leak at the surface and when I come up it's essentially flooded. Took it to an aqualung shop and they said it's fine. They took it apart and put it back together and said it was ok. It works fine to dive, but it's a pain to have to wobble around to get air away from the valve. Any thoughts?