I have been using an iPhone 4 I purchased in the UK with AT&T in the US for the past year. After many friends reported not receiving some of my text messages I purchased a new iPhone 5 with T-mobile and thought my problems were over Now the same thing is happening with my new phone! It's not all text messages, just occasional ones - standard sms, not iMessage. What could possibly be causing this?! I restored my new iPhone from my iCloud backup - could there be an issue with this? I've reset my network settings numerous times. Help please!