Thank you to both of you. The suggestion of forums.php has worked and it is now clearer to me what is needed and what is going on. I’m afraid the documentation on Theme Compatibility was not clear enough for people like me who are bumbling around with WP. Perhaps more of an idiot’s guide and explanation is needed for those over-whelmed at first when trying to get to grips with it?
But despite this, this is much better as a plug-in than it was when bbpress was first started.