I've been trying to get a NetBSD machine's /etc/exports to match up with a Sun
   4.1.3's /etc/exports file but am having a problem with some of the mount
   points.  Here is the /etc/exports file:

   /u/vols    -ro
   /u/users

   [...]

   Can NetBSD-1.0/i386 have multiple mount points from the same file system?  This
   works on the Sun, if that's any justification.  Am I just missing some options?

Yes, but you currently have to specify it like this:

/u/vols /u/users -ro

or:

/u -ro

Without launching into a lecture about NFS (in)security, I'll just add
that NetBSD is being more upfront with the effective permissions
you're setting.