no what I mean is this section of includes/languages/english/header.php
Code:
// added defines for header alt and text
define('HEADER_ALT_TEXT', 'Powered by Zen Cart :: The Art of E-Commerce');
define('HEADER_SALES_TEXT', 'TagLine Here');
define('HEADER_LOGO_WIDTH', '192px');
define('HEADER_LOGO_HEIGHT', '64px');
define('HEADER_LOGO_IMAGE', 'logo.gif');
Now this is were I assume you set that define because the code that is a problem is classed as "logo".....
oh and I checked your stylesheet again and you haven't made the fixes for calling the images relatively......doing it the way you are will throw secure error as your are trying to call images on a secure page (login, checkout,etc...) through the stylesheet by pionting to the unsecure side of the site.....when called relatively they will automatically be called secure