I receive this message quite often when sending sms. Contacted ATT- told me character length > 160. Not true...some messages simply state, "I love you" to my husband. Decided to play around last night and see if I could consistently duplicate the error message. I discovered the messages bounce back with "invalid pdu content" when my phone displays 2 or fewer bars. Unfortunately this is normal reception for my house. We tried google talk and the messages go through even though I show no bars. I'm using the stock messanger on the phone. Any advice for a different sms? Does anyone else experience this problem?