Now with a DDB-enabled kernel, booting the machine until the /etc/rc.d/ls
script (which just does an ls /dev)...

Breaking into DDB after the machine hangs and doing a trace (sorry, I'm
not going to retype it all) shows that I'm interrupting the idle loop.

Off the top of my head the only thing I can think of is that maybe the NFS
client code is expecting further packets from the server, and that ls is
blocking on this. Thoughts?

I'll take another look tomorrow, when I'm a bit more awake.

-- 
Gillette - the best a man can forget