On my site http://colnect.com I've implemented the "Facebook login" button and on some pages the "Facebook like" button using FB's new JavaScript API. It all appears to be working seamlessly on ff/opera/chrome etc.
It seems like a problem with Facebook's JavaScript API which happens on some browsers (I've gotten reports for older IEs and browsers of mobile).
Seems the JavaScript code is appending fb_xd_fragment parameter to the request URL and thus creates leads the user to a blank page. I've found a similar question (yet different which is why I opened this one) on: http://stackoverflow.com/questions/2955012/facebook-javascript-sdk-fb-xd-fragment
The solutions presented there weren't helpful.