Post update blank page on catalog - need advice

So I finally got around to updating to 1.5 from 1.3.8. The update appeared to run smoothly. I can get into the admin area and it is happy with everything, but when I go to the live catalog I just get a blank page. My first thought was that it must be my custom template so I set it to the default one but that didn't change anything.

I did the update by replacing all the changed files from the new version into the folder of my site. I of course have my entire site folder and database backed up but I was wondering if I can get some expert help in going about this the right way?

The site is not an active site but the catalog is located here: https://www.garudaillo.com/kinderbooks/zen/ (just a blank page or error notice depending on the browser).

Which steps in the detailed upgrade instructions did you skip? https://www.zen-cart.com/upgrade

FAQ article on blank pages: http://www.zen-cart.com/content.php?124-blank-page

Looking at the logs, it looks like I'm getting a fatal error with the bmz image handler:

[04-Jun-2012 18:18:08] PHP Warning: require_once(/home/content/i/l/l/illo1620/html/kinderbooks/zen/includes/classes/bmz_image_handler.class.php) [<a href='function.require-once'>function.require-once</a>]: failed to open stream: No such file or directory in /home/content/i/l/l/illo1620/html/kinderbooks/zen/includes/functions/extra_functions/functions_bmz_image_handler.php on line 13
[04-Jun-2012 18:18:08] PHP Fatal error: require_once() [<a href='function.require'>function.require</a>]: Failed opening required '/home/content/i/l/l/illo1620/html/kinderbooks/zen/includes/classes/bmz_image_handler.class.php' (include_path='.:/usr/local/php5/lib/php') in /home/content/i/l/l/illo1620/html/kinderbooks/zen/includes/functions/extra_functions/functions_bmz_image_handler.php on line 13

I'll see if I can get that updated correctly.

OK, image handler 4 fixed the blank page, now I just need to get the custom template that someone created for me updated to work with 1.5. Thank you!