For the past 2 months I have had problems sending text messages. It is not location specific. It happens at home, at work, when I was in a different state. Also the recipient of the message or it's size does not seem to matter. It does not happen all the time. The only way I have found to get them to send is to send them while it is still processing (little blue circle chasing itself) restart the phone. When it restarts is asks if I want to send the messages when I have digital service and will send then immediately. I have downloaded the most recent version of Handcent and have even reverted to using the message service pre-loaded to the phone. I am at my wits end. I have an Droid DNA by HTC.
