Been using Google Voice since I got my iPhone 3gs, and while the GV app sucks, with it's terrible load time and non landscape keyboard, it was doable. Now, it never seems to ring. It alerts me of the missed call, and the voicemail, but doesn't ring. My girlfriend, using an iPhone 4, is experiencing the same thing. Yes, I checked both phones, neither are set to "do not disturb" and the phones are both selected in GV to ring when people call.