3g wont work anymore.

Ever since I tried to install a software name duokan my kindle dx started to act weard. When I plug in via usb on my computer and try to send some file it will disconnect, (is not my laptop or my usb cable).

And my 3g service stoped working (I was able to send files to my kindle email and that way it will appear on my home screen section)

I tried restart from factory default settings and calling amazon support.