Hi s.white,
If you get an error "The URL from which web form was submitted is not within a selected refferer list." it usually means that someone downloaded your web form and tried to submit faulty values to your web form.
In order for the web forms to be a bit more user friendly, we include the actual URL from which web form was submitted in the email that we send, therefore you will know for sure if the data was sent from valid source, or if the source is faulty.
In Step 1 of 9 of the web form setup, you have the option of entering the URL which will host the web form. You need to make sure that this is a valid host website.
I hope that this helps.
Ronen