I'm running 1.2D on my file server. I've been slowing upgrading other
machines to 1.2G, and won't get to my file server for another couple of
weeks, but I'll hurry up if someone says this is fixed.
  I have crashes when I do a lot of disk activity. e.g. copy a directory
tree from one drive to another, or between partitions.
  Trace from KDB says:

sd0: dk_busy < 0
disk_unbusy
sddone
scsi_done
ncr_complete
ncr_wakeup
ncr_intr
Xresume
idle
bpendtsleep
ncfssvc_nfsd

  I often also get errors about a CCB having already been completed, or 
some such. When the machine finishes fsck'ing its 6Gb from the last crash,
I'll be happy to dump anything that might help. Please tell me.
  I have posted dmesg output for this machine to the list before, and I'll
email to anyone that wants it.
  This is a Symbios NCR card. My drives and controller are Ultrafast+wide, 
but I have the controller set to do 20MB/s instead of 40, since it seems
to occur less often.
  I suspect something like the data becomes ready prior to the driver
even finishing setting up things. Does this make any sense?