I use my shuffle as an audio source for a voice mail system. It works, but needs to be charged every day. I got a USB / AC adapter which charges it just fine, but it won't play when charging. Is there any way to make it play while charging? If someone has made a shuffle play while charging, please tell me how it was done - I've tried it while connected to a computer and my AC adapter with no luck - power on then plug in and plug in then try to power on.