z index problem in Safari

Hi guys.

I have a page with a .swf file on z-index 1 and css/html content on z-index 2. In firefox and Internet Explorer this works fine, in Safari as well, but the problem is if I rollover the navigation, the navigation disappears and only comes back when resizing the window or reloading page. any ideas how to fix that?

page is here:
http://www.nicolegulotta.com/test/portfolio.php

thanks a lot
co