I bought this router 1 month ago to use with 4g/3g connection. Initially, the ussd feature worked without an issue. I tried it today to recharge the sim and it would not work. I figured i should re-install the firmware. I downloaded the offcial revC firmware from the dlink support page and now it's stuck at 96% since 40 minutes. I don't know what to do - i am afraid to unplug it. Please, i need urgent help on this one. Thanks