It's worth spending 10 minutes rooting around in the config for a template (for instance - limit it to just a single category, default new documents in that category to pick up the template, etc).
It's very simple to use, does just what it says on the tin.
I had a great response from Mike and with thanks to the magic words it's all fixed.
Mike is now at the top of my donation list. I give 50% of any donation I get for Joomla extensions on to another developer... help me, help Mike. :)