Just got a new 8110 (on O2), and had it unlocked for use with Tesco Mobile (which they tell me runs on the O2 network). With the Tesco SIM in place the phone shows full signal strength, 75% battery and displays "Tesco" on the screen, but yet will not send or recieve calls or SMSs. Immediately upon making calls, a "Call Failed" message is displayed. Help!!!
