wp-comments-post.php half working

Hi there,

I’ve got a site setup whereby comments work fine however when I try posting on a preview page I get redirected to a blank wp-comments-post.php page.

Any ideas on where to start troubleshooting this?

I’ve got the following line in the comments.php

<input type=”hidden” name=”redirect_to” value=”<?php echo htmlspecialchars($_SERVER[‘REQUEST_URI’]); ?>” />

I disabled permalinks and that still did not work.