Hi cdg,
 
> >Description:
> 	FS unmounting/'clean' code can cause system to crash on reboot,
> 	and can leave file systems incorrectly marked 'clean.'
> 
> 	This is probably the cause of some of the hangs on reboot
> 	that people have been reporting.
> 
> >How-To-Repeat:
> 
> 	cd /usr/src/sbin/init ; make ; make install ; reboot
> 	note crash and/or trouble rebooting.  on reboot:
> 	fsck -p
> 	note that fsck says that root file system is clean.  then:

init and newfs (mount_mfs) are in use when the new version replace the old
files so you need to rename this files and remove it later, but i am not sure
at the moment if that works or if you need to reboot and then remove the old files.

Bernd