hai per caso cambiato la SIM di recente, operatore, o sei stato all'estero?
perche' ho trovato questo messaggio interessante:
I have just experienced this exact problem on my magic.
The way to solve the problem is (at least in my situation - returning from a holliday in France)
1. Choose SETTINGS - WIRELESS CONTROLS - MOBILE NETWORKS -
2. uncheck everything unnecesary ie. "Data Roaming" and "Enable always-on mobile" -
3. Change setting on "Use only 2G networks", wait 10 seconds, then change it back.
4. Now try NETWORK OPERATORS. Here you will get a network error (Not the "com.android.phone" error)
Just continue and you'll get your wanted network.
The reason for this behavior is that android uses a new type of network and supports old ones.
Some countries dosen't use this new network.
When your android phone makes a handshake in these countries it'll accept without error, but when it returns to the new type it won't connect.
This must be a bug and you can solve / workaround this by doing the above
prova anche tu a fare come descritto (in wireless e reti, reti mobili)