yup, same problem here. I've been having other issues with my phone so I ended up updating to 4.1.2 to see if that would resolve them. Along with it was AT&T to update all their worthless apps which apparently has ****** up the text messaging on my phone as well. I have it default to the normal text system and the messages still appear there, but I have to go into text messaging to get it instead of just pulling down and clicking on the message.
If I do that, it immediately prompts me to enter my voicemail password (which I have never known, don't want to know and don't see what it has to do with a ******* text), so I have to go back to the home screen and go back into text messaging to do anything.
So sick of AT&T's wanna be iPhone bullshit apps that nobody uses and are complete garbage.