I have edited the page.tpl.php file to include an image in the header and another in the footer of the page.
When I am in the home page of the site ie. '/product_range' the images are there. If I navigate to another part of the site ie. '/node/1' they are missing. Coincidently this is actually the same page just referenced differently in the url.
In the page.tpl.php template I have referenced the image like this:
<img src="<?php global $base_path; print path_to_theme(); ?>/images/brand_icons.gif" alt="" />
This is the actual path to the images: '\sites\all\themes\MySubTheme\images'
This is most frustrating... Thank you in advance for your assistance.