Error message with Nelo theme and membership.

My Nelo install seems fine until I install the membership plugin. Whilst logged in everything seems ok, but when I log out I get the following error message on the front page: (Doesn't matter whether membership is enabled or disabled... error is still there.) Lose all the front page content and the page links. I am using the custom homepage so there are no posts on the home page.

Warning: Division by zero in /home/ukpages/public_html/wp-content/themes/wpmu-nelo/functions.php on line 121

Line 121 is: $max_page = ceil($numposts /$posts_per_page);