jQuery Modal positioning error in Google Chrome

I'm using a modal to display a contact form on top of a flash video.
The problem is that they modal doesn't seem to overlay the entire page
in Chrome (ver3 & ver4).
Example :
(google chrome bug)
http://i36.tinypic.com/szdi5d.jpg
(any other browser)
http://i33.tinypic.com/2e0k3k3.jpg
I'm not sure if this is a Chrome issue or a jQuery Issue.
Ideas?