Error with github.js #8

Hi, I get a small error on your script when trying to do a post.

When I try: gh.user(username).forkRepo("brianleroux", "wtfjs");

I get

TypeError: 'null' is not an object (evaluating 'iframe.contentWindow.document') on github.js line 66

I was wondering if you knew a quick solution to this problem? Is it because I am developing locally? All of your other functions work great just nothing to do with post().