nice!!, so there never was a good kernel version.
In this case I guess the right question is, is
what/where is the shutdown mechanism(in the kernel)
responsible for this and if possible is there already
some mechanism in place for this machine with this issue
i.g. I had to add my machines dmi info to reboot.c
in order for it to reboot properly.
Now keep in mind this could have nothing todo with
adding some dmi entry, this could somewhere else
(which the bisect could reveal(hopefully)).
as for debugging I normally use ohci1394_dma=early
you might be able to catch some strace towards the end
Justin P. Mattock