Hmm, saw the Apple Support doc you linked to, the command is effectively identical to the one above as /Volumes/Macintosh HD is a symbolic link to /.
Could you paste in the output from the following Terminal commands?
ls -laFd /
ls -laF /Volumes
mdls /
(Note, these commands don't change anything.. they just display the Unix directory info and metadata attributes)
Thanks!
Macintosh:~ Pete$ ls -lafd /
drwxrwxr-t@ 38 root admin 1360 Nov 1 03:31 /
Macintosh:~ Pete$ ls -laF /Volumes
total 72
drwxrwxrwt@ 7 root admin 238 Nov 1 03:26 ./
drwxrwxr-t@ 38 root admin 1360 Nov 1 03:31 ../
-rwxrwxrwx 1 Pete Pete 82 Jul 29 13:01 ._BADZMARA*
-rwxrwxrwx 1 Pete Pete 82 Jul 17 15:06 ._PETER WU'S*
-rwxrwxrwx 1 Pete Pete 82 Oct 14 13:17 ._peteNano*
lrwxr-xr-x 1 root admin 1 Nov 1 03:26 Macintosh HD@ -> /
drwxr-xr-x 1 Pete Pete 20480 Oct 30 20:55 Vista/
Macintosh:~ Pete$ mdls /
kMDItemFSContentChangeDate = 2007-11-01 03:31:24 -0400
kMDItemFSCreationDate = 2007-04-28 02:20:37 -0400
kMDItemFSCreatorCode = ""
kMDItemFSFinderFlags = 16384
kMDItemFSHasCustomIcon = 0
kMDItemFSInvisible = 1
kMDItemFSIsExtensionHidden = 0
kMDItemFSIsStationery = 0
kMDItemFSLabel = 0
kMDItemFSName = "Macintosh HD"
kMDItemFSNodeCount = 34
kMDItemFSOwnerGroupID = 80
kMDItemFSOwnerUserID = 0
kMDItemFSSize = (null)
kMDItemFSTypeCode = ""
kMDItemLastUsedDate = 2007-11-01 03:32:13 -0400
kMDItemUsedDates = (
2007-11-01 00:00:00 -0400
)