I don't understand why I don't ALWAYS get ringtone notifications when text messages arrive. Is it because I'm using a proprietary app or is it because the phone just fails to sent a ringtone with a text message arrives? This is very inconsistent. Sometimes a message arrives with a ringtone but subsequent messages in a thread fail to sound when they arrive I just get vibration alerts that a text has arrived. I often miss text messages when I'm not holding my phone or it isn't close by.