When a bootstrapped addon is shutdown, any global frame scripts it has previously loaded with the allow delayed load flag will remain and continue to execute for new tabs. Every time the addon is started without restarting the application, frame scripts multiply. Hopefully a solution similar to bug 481603 can be found.
Olli, it does strike me as strange that there's no way to stop a content script from being loaded in the future, but I'm surprised that this hasn't been an issue until now.
Is this on Aurora (Fx9)?
Documentation updated: https://developer.mozilla.org/en/XPCOM_Interface_Reference/nsIChromeFrameMessageManager https://developer.mozilla.org/en/The_message_manager https://developer.mozilla.org/en/Firefox/Updating_add-ons_for_Firefox_9#Bootstrapped_add-ons_can_remove_delayed-load_scripts Also mentioned on Firefox 9 for developers.