I use Go SMS and set it as default after clearing defaults for AT&T messaging in applications. If anything asked I selected Go SMS. I remember it being a pain but, I don't get notifications for texts just phone calls in AT&T messaging.
Sorry, I just don't see this option and I'm hoping you can help me recreate what you did to disable text message notifications in the app (w/o disabling voicemail notifications)? e..g, I go into the main
SETTINGS > Applications, where the only relevant option appears to be
Manage applications; but Manage Apps just shows the list of installed apps (downloaded, all, on SD card, running). I find AT&T Messages in the Downloaded list, and upon clicking it I see options to "force stop", "Uninstall" and "Clear Data". None of these seem like they'd do the trick; could you provide more info on what you meant by "clearing defaults for AT&T messaging in applications," am I looking in the wrong place?
BTW, you're on a Samsung Galaxy S2 as well, yes? If not, maybe you're seeing an option I'm not under Settings > Apps?
Thanks in advance for any help you can offer, these double text msg notifications are a total pita.