I've just installed AirDroid on my tablet, and am trying to connect with my PC. But when I open http://web.airdroid.com/, I get just a pretty picture on my screen, with nowhere to enter the passcode. I'm using Firefox 18 on Windows 7 (64-bit). I've tried opening Firefox with all add-ons disabled, but this makes no difference. Can you suggest any reason this might be happening, and what I could do in order to log-in?