Chosen Solution
My iPhone 3Gs will play all tones EXCEPT the SMS/text tone…doesn’t matter which I choose, all I get is the vibrate. I’ve restored my phone (not as a new iPhone), done a number of hard resets and power downs. Any answwer?
Is your phone jailbroken? If it is you can SSH into it and remove any metadata files which may be corrupted, it’s the only thing that I can think of that will cause a quirky issue like this.