After upgrading to Mountain Lion, my MacBook has been stuck twice in a way that every app slowly becomes unresponsive, including menu bar (but a bit surprisingly, not Dock).
The only symptoms common to both times have been:
- Airport connection dropped just before laptop getting stuck
- Both times the last symptom before I've rebooted the laptop have been
kernel[0]: disk3s3: media is not presentmessages in Console. As I'm not able to open Console when the Mac gets stuck, I'm actually not sure if these messages come after I've pressed the reboot key combination or before it.
Any ideas why this is happening and how to prevent it from happening in the future?