i updated my iphone 2g to 2.1 a few days ago and did everything like normal restore unlock....the normal...this time when i turned it on there was no signal..it has recived one text message but thats it.....i left the sim in for 3 days..nothing. everything else works...internet, bluetooth, youtube. iv tried to downgrade up grade idk what to do plz help im not afraid to use the thank button