Regarding your issue, I still not able to replicate 'undefined' issue. Have you try clear your browser cache and see if you still see 'undefined'. As for opera, not sure why my machine not able to access your site. I get these error http://take.ms/ncEQt Anyway, I did ask my other colleague to access your site with opera and they do not get that 'undefined' too.
I also tried with chrome, firefox and safari and non of them show 'undefined'.