>This doesn't appear to be an old drive ... how many bad sectors do
>people usually tolerate before ditching the drive?

Zero.  If the drive is detecting bad sectors, then it has developed more
bad sectors since its factory scan and will probably develop more as time
goes on.

If its a SCSI drive, you might be able to pull all the data you can off
and initiate a low-level format of the drive with the scsictl command.
That will tell the drive to lay down new sector markings and do another
bad block scan.

If you still get bad block messages after that, turn the drive into a
paperweight.