Well, this is really great. There’s a couple of bugs in WebDriver that I can’t solve and this was one of them. Reproduction cases are in the ticket but essentially sometimes Firefox would just complain that it didn’t have permission to do standard things like click on a link or focus on an iframe.
I ran into it a couple times and my hack was just to ignore the exception and try the offending action again before continuing bravely on, as it sometimes threw the exception while actually performing the desired action. Glad to hear this is fixed in FF 15.
Along with the announcement of Apple Sauce and Android Sauce, all my blocker issues for test automation are dropping like flies. Yay :)