There is clearly a problem. I also get this 400 error-code. I use it thru 3g network. The Web UI works perfectly anywhere else... even if I use it thru phone browser... but it won't work using uTorrentMobile. So, please... instead of think users are doing something wrong, try it in one of those phone models... I'm using a n97. So.. here is my advice for those who can't use the application. Open your internet browser and type: http://username:password@YourIp:PortNumber/gui/ for example: http://john:12345@200.170.1.1:7089/gui/ (please, insert real values...) It works pretty fine as well... you can monitor and even add downloads from file system or url link. See ya.
