Thanks acrylian for getting back to me so quickly. Yes the theme is up to date. I think I have a fix:
After installing the night build JIC I clicked on the plugins tab and clicked the 'i' icon for information and it states,
"Place a call on the function printCommentForm() in your script where you wish the comment items to appear."
I've added:
<div class="ten columns">
<?php printCommentForm(); ?>
</div>
to pages.php
and it works.