Having a play with my stage reg, removed the button gauge and put an spg on a 6" hose. The hose was brand new, given to me by Stu. Onpened valve slowly and heard a hissing, closed valve and checked din wheel and put a bit of spit on soem of the bits I had changed- nothing.. Opened valve again and heard hissing again, then noticed this! Going to need a news hose. Scary thing was I had my face right next to it trying to find out where the leak was.