I had the same problem, apparently jQuery 1.6.1 is the problem, don’t really know and I wont bother to find out yet.
You have to upgrade the WordPress jQuery file, or use your own. I find it easier to upgrade the WP core file.
wp-includes -> js -> jQuery -> jquery.js
Go to jQuery’s website and download the latest version, which is 1.6.2 , everything should work fine after that.
