Hey Guys, Yesterday, I booted up my iBook, but wasn't greeted by the startup chime. Leopard booted up fine, so I made sure the volume wasn't muted. Thats when I noticed that the menu bar did not show the volume control, and when I pressed the keyboard shortcut, the normal animation popped up with an "X". System Profiler said that there was no audio output device found. I shut down the computer and removed the battery. After a few moments, I replaced the battery and turned it on. Still no startup chime, but all sounds worked fine once OS X loaded. Now it seems that everything works fine, I get the startup chime, and System Profiler recognized the output device again. Any ideas on what caused this issue, or how to prevent it in the future? Thanks!