i have 5 bars of service. when i send a text it either takes forever to send or it says message not sent please try again and a red triangle pops up next to the message. i also dont recieve texts half of the time and cant call people unless i try to call them 5 times in a row. i have a nexus s 4g. i have encountered quite a few problems with the phone but they all seem to occur after i download an app. this messaging problem makes me wanna break my phone in 2. has anyone had it and know how to fix it?