Ok...I compared the 2 tpl_header files, the one in my override files and the one the other template that worked...they both match...so I'm assuming that's not where the problem lies. Here is the one from my override file:
<div id="logo"><?php echo '<a href="' . HTTP_SERVER . DIR_WS_CATALOG . '">' . zen_image($template->get_template_dir(HEADER_LOGO_IMAGE, DIR_WS_TEMPLATE, $current_page_base,'images'). '/' . HEADER_LOGO_IMAGE, HEADER_ALT_TEXT) . '</a>';
Do you have anymore ideas of where the problem is? As soon as you add something to the shopping cart, then proceed to checkout, that is when my logo disappears. You see a blank white square with a with a red x in the upper left hand corner and words that say: Powered by Zen Cart: The art of E-Commerce. It happens at the customer log-in page, the same page where they can enter in customer information.