I have a Samsung galaxy Ace Duos I589. After about 20-30 minutes of inactivity my phone seems to drop of 3g and turn to 2g signals. I cannot seem to get the phone to reconnect to a 3g signal unless I restart the pad. I've changed the settings in network mode to WCDMA only and the when the signal drops I seem to get no signal whatsoever so I have to restart the device.