Hi Paul.Ive just done what you said. my currency codes is on. should this be off?Im wondering why, just in the last week that this has happened. I have changed nothing in my settings. 

My theme is also Dawn. I have just updated to Dawn 13 and still the double price is displayed at checkout. Grrrr 

Hi Paul. Im having this exact problem. did you get yours sorted? I have tried everything to fix this.