Yup - already checked out that page and I couldn't get it to work. I'm thinking probably because I'm trying to do background-size:contain and not cover...?
It looked reaaally bad with cover... so I'm thinking that won't work. Hmmmm... surely there has to be a way... javascript, jquery, something. The first VP of the museum uses IE8 and won't upgrade - so I don't have a choice but to make it work. I don't have to go any older than IE 8 though.
http://internationaltowingmuseum.org/
If you're trying to use background-size: cover, check out this post: http://css-tricks.com/perfect-full-page-background-image/
I have created a background-size polyfill for IE8 that is really simple to use:
.selector { background-size: cover; -ms-behavior: url(/backgroundsize.min.htc); }