Originally Posted by day_trippr
I would definitely take the time to remove the regulator from the tank and make sure there's a gasket tucked inside the regulator coupler...
Forgot about that one - whoops. Had that problem too.
Check the *type* of washer if you have one. Rubber washers are single use and won't prevent a leak over time. Nylon and Teflon washers are multi use. They're hard, ~1/8" thick, and white or clear. Your gas supplier should be able to sell you one cheaply.
Side note - the regulator-to-tank connection i have is intended to seal at the washer and isn't meant for Teflon tape.