I've actually had to (temporarily I hope) remove this mod from my threads because there is a bug with Internet Explorer that causes the page to be blank and reload in the browser with a different url.
http://blog.facesharp.com/2010/10/05...ing-analytics/
It's causing some serious issues with Analytics, SEO, etc... This particular link mentions it's IE6 an the XFBML implementation but it has also been reported with the iframe and newer ie versions.
When I checked my google logs sure enough this was happening at my site too.