As far as I can tell the Mozilla addons page doesn't like addons running on it. I'll add a more explanatory error message though. I hadn't thought to test it on

As far as I can tell the Mozilla addons page doesn't like addons running on it. I'll add a more explanatory error message though. I hadn't thought to test it on HN, so that's intriguing. I'll look into it, but I'd presume it's due to some sort of quirky DOM structure.