Seems to work on one tab at a time. If you load a new tab of Facebook, the redirect happens again until you disable and enable this addon, and reload the tab. Be nice if this was a bit more constant.
Unfortunately I can't do anything to solve this issue as it's reason is that Firefox sometimes just stops or doesn't load the Add-on. This seems to be a Firefox bug. Changing my code doesn't help here.
Reloading the tab forces Firefox to reexecute the Add-on. It's not a great solution, but it mostly works.
