I am just not seeing what you are looking at in either Firefox or IE. Possibly I don't understand the problem. The image mentioned is centered on the page. There is some slight differences in opacity between the browsers, but you may not have coded for both browsers.
Been up all night working on pages so may not get back to you until later tonight.
Fixed it buddy
If you have a look now you'll see what I meant
Many thanks for your time, patience and expertise on this