I am experiencing this EXACT same issue. I work with constant contact while using Mozilla Firefox. I alter the code to my liking, adding background images in the style sheet and everything works fine. When I send myself a test email in firefox it opens flawlessly! But, however when I read that SAME exact email in another browser like Internet Explorer 8, the images do not show (just the image box) , the css code for the background images does not seem to work either. It is VERY annoying because how am I to know how many of my contacts actually use IE over firefox?