This morning, I had a problem with my sound not working on my Ubuntu 12.04 machine. Strange, as it usually works. Whenever I'd log out, I'd hear the familiar Ubuntu conga "dadadump", so sound was working, just not for my user account.
So, I rebooted my machine, and reminded myself of the shutdown bug that has been plaguing me on several machines now where the kernel panics. Argh!
After rebooting, I resolved myself to find out what the deal was. Initially the messages lead me to believe it was Dropbox causing it, but it was innocent and just happened to be running when the machine hung.
fglrx hard lockup on shutdown
dding "nomode" to my GRUB_CMDLINE_
It's the Linux way: scratch one itch, and finally remove the scab you didn't realize was able to be healed.