File "resource://anonid0-reddit-panel-at-jetpack/api-utils/lib/content/symbion t.js", line 177, in _unregisterListene this._frame.removeEventListener(this._loadEvent, this._loadListener, TypeError: can't access dead object This exception is due to HiddenFrame module that is cleaned before Panel/symbiont so that iframe used by Panel/Symbiont is removed before the call to destroy method of symbiont that leads to this exception. This `this._frame` object is a reference to an <iframe> node created by HiddenFrame which is already removed from DOM when Symbiont.destroy is called.

(I don't think we were leaking anything here, it is more likely to be an issue where we call a destroy method too lately or in wrong order)

Commits pushed to master at https://github.com/mozilla/addon-sdk https://github.com/mozilla/addon-sdk/commit/4b614c6e843492726d059d8d0059750daaca4e01 Bug 751211: Fix reddit-panel tests. Fix destroy/unload methods call order between Symbiont and HiddenFrame modules. https://github.com/mozilla/addon-sdk/commit/252364b8729c8181abd25461d3f9e4902167a977 Merge pull request #424 from ochameau/bug/751211-fix-reddit-tests Bug 751211: Fix reddit-panel tests. r=@gozala