I was trying to share a folder in OpenSolaris 2009.06 using the
"System->Administration->Shared Folders" with Visual Panels installed and also
using the share command. Both worked until I wanted to restrict the rw access
to a certain hosts.
# share
-               /test   rw   "Test"

I could mount the /test on a Linux hosts, but once I changed the access to a
subnet with my linux hosts, the share output was:
# share
-               /test   sec=sys,rw=@172.20.15.0/24  "Test"

The linux hosts could no longer mount the FS with a message access denied by
server. I fixed this by removing the share and doing the same thing using the
zfs command.
# zfs set sharenfs=rw=@172.20.15.0/24 pool/test
# share
-@pool/test      /test   sec=sys,rw=@172.20.15.0/24   ""

Once I did that, the linux hosts could again mount the /test. 

It's apparent that the output are not the same and that the "Share Folders" and
share command do not work as expected in this case.