In our site we trigger popup window with form being submitted with POST method and target="_blank". This is done so it opens 3rd party web app in new window. However, when popup windows are blocked for our page it (correctly) blocks popup, asking user if it should allow popup window. No complaints here. However, when user allows page to show popups, or allows for a single popup, while it opens in new page - it tries to open the URL with GET method, and not with POST, as originally intended, breaking our app. Now of course user can just re-trigger the form and now with allowed popups it will work. But should user not want to allow all future popups to be shown, there's no way for them to open a single popup with firefox switching method (and possibly losing form data?)