I have been listening to books using Audible. I have a set of headphones attached. I find that if I leave it attached and stop listening (either charging or not charging), often after several hours I go back to use it and there is no sound. I try unplugging the headphone at that point and there is NO sound. Rebooting brings back sound. I have not tested unplugging headphones while idle but will. However is there a reason why leaving headphones plugged in causes a sound issue?