That embed code looks fine, looking at your HTML it looks like you don't have a doctype try adding the doctype below before your HTML tag.
Add the following to the top of your doc before your HTML tag and clear your browser's cache.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
You also have an extra </script> tag just before your </head> tag.
If it continues to works in Firefox, but not IE you could try validating the page and fixing the errors, beyond I would need to take a look at a live page.
SimpleViewer Support Team.