dualslider problem in IE with images

Question

I downloaded dualslider and changed the first and second vimeo movies to images.

dualslider works on jquery.

FF and chrome don't have any problem but IE8 splits images to three and slides.

Please see this test with IE8.

I noticed that if I add at least one vimeo or youtube video, IE8 slides normally as well.

I wrapped all three images with object tags, but it did not work.

Could anyone know the cause and solution?

Thanks in advance.