Ran into a weird one now.
On FireFox 30.0,when I include weinre in my html 5 page (for a hybrid mobile application), window.sessionStorage.setItem
is suddenly not a function any more (or does not exists or something).
Remove weinre script, and all is fine again.
In the actual Android web container on the mobile device, it seems fine again.
So, not a train smash, but very annoying.