@bevis. Thanks for posting. I don’t know what you mean by “turned off the editor”. The first thing you should do is toggle the editor to see what the underlying html is.
Your template should not have anything to do with it. It is most likely the editor. it could also be filtering issues. Have a look at the FAQ.
What version of the plugin are you using?
If you want me to look at the site. Email me with a temporary admin login and your order number.