On numerous occasions when I view photos/videos in the photo gallery and try to go back the phone locks up and shows a black screen. You can press all the buttons you want and nothing happens. You press the power button to turn the screen off and on and shows you the lock screen. Once you slide it, it takes you back to the frozen screen. After about 1 minute it un-freezes and you have to task kill the gallery to go back into it to view pictures/videos again...UGH!
This happens on my friends Atrix as well.
This happens on my friends Atrix as well.