The error you see is-
Stopping identd services: user_memory_flush_task:
memory not in hash table
Kernel panic: user_memory_delete: fatal bug
This is a very old bug, and has been fixed for several
months, but the kernels on ftp.mklinux.org in the pre-R1
area are also very old.
and use that instead of the vmlinux that's currently in
your /mach_servers directory. The problem will go away
after the next reboot.
If you still have the old kernel and need to shutdown
you can kill identd -before- running the shutdown command.
killall -9 identd
will kill identd and prevent the kernel panic at email@example.com