its not flickering, i thought the same thing. was it sunny in your area. when the weather app loads on the homescreen it flickers in the top left (its really a sun shine ray).
The Screen is turning on and off like if your on a call... its doing dim bright dim bright buggin out on me... haha I'm like ahhhhhhhhhhhhhhhh WTF!!!!!!! STOP!!!!!!!!!!!
Then i turned the Brightness all the way up and it sorta stopped... I called Sprint they said go back to Best Buy haha I'm like GREAT!!!
i was having the same problems during calls...i think its in the settings. Cuz the screen would go black and would wake up when i moved. So i think its just an auto wake up setting or something.