Doesn't work in firefox 19-22

[fellz]

Sadly i see this in firefox 19 and nightly build 20
[17:43:57.390] ReferenceError: event is not defined @ http://localhost:3000/client/mello.js?3eb9fa1cb0001946950c0f57a13a151329811aa7:112
Error appears when i type in New task input field and in subject field (text area).