Well, it's been a long 48 hours.  I believe the problems may have 
been solved by resetting the PRAM on my 840AV.

HOWEVER, does anybody have any advice about disklabels?  I have a 
quantum drive which is mounted at /dev/sd1c but the core information 
from disklabel -r show that /dev/sd1g is formatted as 4.2BSD.  Is 
this OK?  Why couldn't I get it mounted at /dev/sd1g?  Why did all 
efforts to write a disklabel come to naught?  Am I just interpreting 
this wrong?