I bought a new unlocked Motorola W375 from E-Bay.It is compitible with AT&T,cigular and other carriers. My carrier is AT&T, I sometime get the signal but sometime i lost the signal and it says 'no service' or 'emergency only'. Someone from AT&T store told me to flash the phone with a software. I want to know what is flash and how can i flash the phone. Please help, thanks a million in advance.