Simplemodal plugin facing a problem on IE8, with a textbox and a link on the main page

Question

Hi I have the SimpleModal working very well on my site.

But i'm facing a problem (only with IE8), i can't resolve. My simplemodal is showing over a banner (jquery powered) that simply do a slideshow. The diferrent image have some link on them.

When my simplemodal is showing, it overlay the banner slideshow. This modal has some textboxes that can't be selected or focused because it try to use the link beside them. In clear, the textbox have a z-index lower than the banner and it try to use the banner instead of the modal texboxes.

Here the demo: www.maceria.com click on the icon in the top right corner with a small human head.

Thanks very much for your help.