Trying to 'Connect' To Trello getting a 'This request came from an unauthorized domain' error

I want to try-out trello for tracking my work, and tonight when I clicked the 'Connect To Trello' link from the 'Boards' page, or 'Connect' from the Trello Settings page I get 'This request came from an unauthorized domain' as the only text in a pop-up window.

Thanks,
Francis