This happens in Safe Mode? *[https://support.mozilla.org/kb/troubleshoot-firefox-issues-using-safe-mode Firefox in safe mode] Also check if your antivirus or firewall are blocking the popup. Did you already see this article? *[https://support.mozilla.org/en-US/kb/pop-blocker-settings-exceptions-troubleshooting Pop-up blocker settings, exceptions and troubleshooting] Also: *[http://kb.mozillazine.org/Preferences_not_saved] *[https://support.mozilla.org/kb/how-to-fix-preferences-wont-save Preferences won’t save] *[https://support.mozilla.org/kb/reset-firefox-easily-fix-most-problems Reset Firefox]

Not sure if this will help you or not. There is a preference for the maximum number of popups allowed from a single domain to keep bad coding or a malicious website from creating an infinite loop of popups. '''dom.popup_maximum'''<br /> http://kb.mozillazine.org/Dom.popup_maximum