when i attempt to make a call, the phone makes the call, but i can not hear it. also, the square that usually says "speaker" now says "handset" and when i click on "handset" it doesnt go back to normal.
also... voice dialing doesnt work. i never hear the words "say a command" and when i try to say something... it doesnt read my voice.
i get the first part when i start a call then plug in my wired stere earpiece to talk through. if i have them in before the call no problems. but if i plug them in after, i get no audio, and the "speaker" changes to "handset" like what you describe. take it to a store and have a tech duplicate the issue. maybe something is triggering your headset plug to think it has a headset plugged in?
