Following the manual for my Sanyo Katana Lx cell phone to the letter, I hit the side camera button to unmute the microphone, which I occasionally mute by mistake. You can also mute and unmute with the left soft key. I've been trying both the camera button and soft key and no matter what I do it won't unmute. It's as if it's permanently stuck in this mode. The microphone stays off and no one can hear me. Help!