Adsense ad in DIV behind transparent Flash not clickable.

At my site http://minigiggles.com I have a Flash player with a transparent frame at the end that reveals a DIV behind the player that contains Adsense code. (If you want to skip to the ad just hit the < button on the player.)

In IE the ad is clickable. In Firefox the ad is viewable but not clickable. (Adsense ads at other sites are clickable for me, so it's something about the site instead of my computer.)

I'm using SWFObject to place the Flash player on the page with wmode set to transparent. Is there something I need to add to the HTML for Firefox to make the ads clickable?

Thanks