The only popup that comes to mind like that is the warning for when you are closing multiple tabs. If you go the Firefox settings (press the menu button on the toolbar and select Preferences), you can check the '''Warn you when closing multiple tabs''' option to bring that back. Other than that, you may have accidentally checked the '''Prevent Site from Creating Anymore Dialogs''' options. When you are on the website that you are having issues with, if you hold down the shift key on your keyboard and press the refresh button, that should allow the website to make popups again. Hope this helps.