There is a known issue with the DivX plugin causing Javascript errors “tagName is empty or not an object”. This is due to the plugin interfering with existing Javascript on the page. Javascript elements that doesn’t use the tagName element will cause the browser to throw an error that stops any Javascript from running on the page.
The only real fix is to uninstall the DivX plugin.
References:
http://labs.divx.com/node/16824
