I may be out of line here, but "disklabel -e sd1" by itself 
without the -r or -R protofile worked for me under NetBSD 1.1. It 
created a ficticous label w/ the correct geometry, dropped me into vi, 
so I could edit the partitions in a civilized manner w/o the need for 
creating an entry in disktab. Is this a bug, or a feature of 1.1? It 
certainly does not work under FreeBSD 2.1. ( I don't know about prev 
versions of NetBSD either).
  I was disklabeling a raw PD optical disk not a hard disk, and it was 
SCSI not IDE, so someone else try it on an unlabeled hard drive and see 
if it also works for you.