ok i had just purchased a google nexus one from California an i had placed my fido sim into the phone, and when i go to make a phone call the screen turns off but the audio is still working, as if it seems to be going into sleep mode possibly?, but the thing is that it wont turn on after this, i can only turn it on by taking the battery out and putting it back into the phone, then it only works. Also when i send texts the phone seems to be working fine.