Screenshot of the issue: http://cl.ly/2oS3
Webpage in Question: http://cure.org
Offending browser: Internet Explorer 7
You'll notice from the screenshot, or if you view this site in IE7, that the background image is not displaying for the content div (#modal-inner-content). Strangely, the image displays in the other divs where it is used (since it's a sprite, I'm using that same image for #modal-top-border and #modal-btm-border).
In all other browsers it displays properly, and even in IE8. I cannot seem to find what CSS rule (or lack thereof) I may be using that IE7 is choking on.
NOTE: in order to get the modal screen, just click the link at the very top banner of the page that says "login to your CURE account