Help GT-I9100 Flight mode on automaticlly !

[699taha]

Hi i have problem whit my Galaxy s II (GT-I9100)
the problem happens only on GSM network mode during a call or active data
network.
the phone turns to flight mode for 5 sec (This ends the call and stop the data
connection ) then flight mode turn off every thing is normal !:thumbup:
but when i make a call or check "use Packet data" in Settings > wireless and network > Mobile networks this problem happen again
NOTE : some times all my apn disappear when i click new apn it shows up "The application Settings (processcom.android.settings) has stopped unexpectedly. Please try again"
PLEASE HELP !