I have a strange issue. I recently upgraded to an Airport Extreme base station and installed a USB disk to share from the base station. I have two Mac's, my MBP and my wife's Macbook. If I try to shutdown my MBP while the airport disk is mounted my system never shutsdown (or restart). If I unmount the airport disk first, shutdown and restart work fine. The Macbook has no problems. Any ideas? The 300GB disk is shared with user level permissions.