[MPlayer-users] dvdnav://1 fails to play

[Roger Pack]

Noticed the other day with a (fairly mundane?) DVD:

$ mplayer dvdnav://
works splendidly

$ mplayer dvdnav://1
basically just results in this message over and over again:

DVDNAV stream read error!

other possible sightings:
http://www.mailinglistarchive.com/mplayer-users@mplayerhq.hu/msg14246.html
http://lists.mplayerhq.hu/pipermail/dvdnav-discuss/2010-June/001216.html
http://web.archiveorange.com/archive/v/yyjk0WtF6hP8c794lzlm

I don't think this is a dvdcss thing.
dvd://1 also works well.

Any ideas here?
Thank you for your support on this subject.
-roger-