may be the vs2 reg, may be the tank reg.
lube the vs2 reg first. put a few drops of paintball gun lube down the asa and dry fire, see if that problem goes away.
meanwhile try the tank on another gun that has both a reg and a gauge and see if that gun also creeps.
if it's a tank with a myth reg, i bet it's the tank. One of those things blew up a droid
