I have spent the last day trying to find a fix for the headers already sent error:
Warning: Cannot modify header information - headers already sent by (output started at /home/domain-name/public_html/shop/includes/templates/orange/common/html_header.php:22) in /home/domain-name/public_html/blog/wp-includes/pluggable.php on line 850
Here is the all too easy fix:
To turn off Canonical URL Redirection, you can add the following code to your theme’s functions.php file.

remove_filter('template_redirect','redirect_canonical');
http://www.velvetblues.com/web-devel...l-redirection/

I hope this helps those that haven't already figured this out. The reason the site was trying to redirect was because of the www or lack-there-of in the url. By that I mean the blog displayed correctly when viewing from http://domain-name.com but did not display correctly when viewing from http://www.domain-name.com

Good luck.