Well unfortunately it seems this error has come back to haunt me. I'm sure I got it working a month ago with the help of the people who posted above but now I have discovered it is returning the exact same error message when COD is selected. I don't know how long it has been doing this but I have tried recloning the shipping modules 3 times, even tried cloning different modules but cannot stop the error from coming up. I just cannot see what I have missed during the cloning process?