Couple more GS2 questions

I had to exchange my first GS2 for another one - now my main problem with the phone is I think I might have done something to the camera settings - as whenever I try to focus the camera to take the pic in certain lower lit areas the camera flash goes off? It didn't do that before, and I can't seem to get it to stop doing that or think of what I may have done to change it accidentally or was it supposed to do that before?

Also, I don't care for how the phone does MMS, but handcent doesn't seem to be working either, as I downloaded it, sent a few messages, and my friends just got blank messages. Are there any other good texting apps? Any suggestions would be greatly, greatly appreciated. (How weird is it that the phone sends pictures as video? Weird, but thankfully due to the awesomeness of android, fixable.)