IE 6/7 problem

Hi: I installed a plugin called wp-greet (http://www.tuxlog.de/wordpress/2008/wp-greet-documentation-english/) – the plugin works great on all browsers except IE 6 and 7. Strangly the plugin designers and others have no problem with IE compatibility and so I seem to be the only one having a problem. Essentially the “preview – send – reset” buttons are not responsive both before and after I installed spam protection. The link to the page is http://tatazara.com/cards/

Thanks for the help
Arezki