Hot answers tagged motorola-photon
According to AndroidCentral and these XDA posts, the Photon 4G is specifically made to prevent access to AT&T or T-Mobile and an unlock code won't do anything. Presumably so that if you are in the US and don't need to roam away from Sprint, you can't switch away from Sprint. The limitation doesn't appear to have been hacked around yet.
As @Mathew Read already said, since your starting again clear the old app data. Settings > Applications > Manage Applications > Select the Messaging App Choose 'Clear Data' and also 'Clear Cache'. If not you could also factory reset the phone.
Only top voted, non community-wiki answers of a minimum length are eligible