Iphone screen goes black during calls. . .
Sometimes while talking on a call, the screen goes black. I can continue the conversation, but can't hang up or access anything on the screen. Tapping on the screen, or the button is uneffective. I just have to wait till it recovers, which can take a minute or two, or turn the phone off. Anybody else experience this?
iPhone 3GS, Mac OS X (10.5.8)