My sister just bought the w600i. Here are some issues: 1. delay when "answering calls", sometimes it wont answer. 2. does not play MP3, "CANNOT PLAY THIS SOUND" comes out, even with default mp3s. 3. when making out going calls, sometimes there is no sound, but the call is being made. we have already updated, and have done a master reset. any help would be greatly appreciated. thanks.