Please try to remove the favorites and the comment form parts to find out if there is a conflict. But in any case there must be any error (browser log, server, ZP logs) or we keep guessing…
Btw, I assume you just include theme custom comment form? You don't need to do it that way. Just create `/comment_form/comment_form.php` (aka same names as on the plugin) within your theme's folder and it loads automatically the theme based one with the standard function. Same works with the contact_form plugin.