Log of shutdown procedure

["Larry Irwin" <larryi@ccamedical.com>]

We are having an odd issue with shutdown on Etch - 2.6.12 #1 SMP Tue Jan 3 
17:35:30 EST 2006 i686 GNU/Linux.
The symptom only occurs if we let a system sit idle for a day or 2 with at 
least one person logged in as root at the command prompt, but not running 
anything.
The next day, if you type:
         shutdown -h now
the system will be begin to shutdown, but the shutdown will stop early with 
these msgs:
         Stopping printer spooler: lprng
         INIT: no more processes left in this runlevel
The main symptom you will notice is that the shutdown process did not power 
off the system.
You must manually power off the system.
At this point, a number of shutdown steps have not been done, including 
unmounting the filesystems.
If the system sits idle for days, with no one logged in, and then you login 
as root and shutdown, it works fine and the system powers off.

How can I view a detailed log of the sequential events triggered by 
shututdown?
I would like to view a single log to determine which item in the shutdown 
process is causing it to hang...

Thanks for any ideas on how to troubleshoot this one...
Larry Irwin