i'm using a NextSIM v2 china3gpp and it worked great for about a week but every now and then it gives me either no signal or "no SIM" error but i know the phone sees the sim because simport lets me see my sim contacts. i know it's making a good connection with my sim card. also twice it's given me a big long error/message on the phone that's in all chinese and at the bottom it says accept or decline?!?!? any ideas?