I think, It's working to my system even in mozilla firefox. If you have not updated your firefox version please update it as soon as possible. Than I hope you must able to use to select the region in which currently you live. . If you want to disable the pop up blocker you may use through as like : .

• Go to Tools > Firefox preference > content > and check out the "block up window".

>>>>>>>>>>>>>>>> If you have still problem;s please come back with screen shots of your system. I'll surely help you out. :) Here, I am dispatching my system's sceen shot that proves that it works simply on my system.