sorry, i prefer at least vlc -vv output and a interface in english.

for me playing dvd is working.

Plays fine here as well. Alexander, you did not provide much data on your configuration, and I cannot read the message in the link you provided.

Can you verify whether your user is a member of the optical group?

$ vlc -vv
VLC media player 1.1.3 The Luggage (revision exported)
[0x15bd1c0] main libvlc debug: VLC media player - 1.1.3 The Luggage
[0x15bd1c0] main libvlc debug: Copyright © 1996-2010 the VideoLAN team
[0x15bd1c0] main libvlc debug: revision exported
[0x15bd1c0] main libvlc debug: configured with ./configure '--prefix=/usr' '--disable-rpath' '--enable-faad' '--enable-v4l' '--enable-snapshot' '--enable-dbus-control' '--enable-nls' '--enable-lirc' '--enable-pvr' '--enable-ncurses' '--enable-mozilla' '--with-live555-tree=/usr/lib/live' '--enable-realrtsp' 'CFLAGS=-march=x86-64 -mtune=generic -O2 -pipe' 'LDFLAGS=-Wl,--hash-style=gnu -Wl,--as-needed' 'CXXFLAGS=-march=x86-64 -mtune=generic -O2 -pipe' 'PKG_CONFIG_PATH=/usr/lib/pkgconfig'
[0x15bd1c0] main libvlc debug: translation test: code is "ru"
[0x15bd1c0] main libvlc debug: checking plugin modules
[0x15bd1c0] main libvlc debug: loading plugins cache file /usr/lib/vlc/plugins/plugins-04081e-f8.dat
[0x15bd1c0] main libvlc debug: recursively browsing `/usr/lib/vlc/plugins'
[0x15bd1c0] main libvlc debug: saving plugins cache /usr/lib/vlc/plugins/plugins-04081e-f8.dat
[0x15bd1c0] main libvlc debug: module bank initialized (395 modules)
[0x15bd1c0] main libvlc debug: opening config file (/home/heaven/.config/vlc/vlcrc)
Blocked: call to unsetenv("DBUS_ACTIVATION_ADDRESS")
Blocked: call to unsetenv("DBUS_ACTIVATION_BUS_TYPE")
Warning: call to signal(13, 0x1)
[0x15bd1c0] main libvlc debug: No Media Player is running. Continuing normally.
Blocked: call to setlocale(6, "")
Blocked: call to sigaction(17, 0x7f30ae81dac0, 0x7f30ae81db60)
Blocked: call to setlocale(6, "")
Warning: call to signal(13, 0x1)
(2297) KSharedDataCache::Private::mapSharedMemory: Opening cache "/var/tmp/kdecache-heaven/icon-cache.kcache" page size is 4096
(2297) KSharedDataCache::Private::mapSharedMemory: Attached to cache, determining if it must be initialized
(2297) KSharedDataCache::Private::mapSharedMemory: Cache fully initialized -- attached to memory mapping
(2297) KSharedDataCache::Private::mapSharedMemory: 4366336 bytes available out of 10485760
Warning: call to rand()
Warning: call to rand()
Warning: call to rand()
Warning: call to rand()
Warning: call to rand()
libdvdnav: Using dvdnav version 4.1.3
libdvdread: Using libdvdcss version 1.2.10 for DVD access
libdvdnav: DVD Title:
libdvdnav: DVD Serial Number: m
libdvdnav: DVD Title (Alternative):
libdvdnav: Unable to find map file '/home/heaven/.dvdnav/.map'
libdvdnav:DVDOpenFileUDF:UDFFindFile /VIDEO_TS/VIDEO_TS.IFO failed
libdvdnav:DVDOpenFileUDF:UDFFindFile /VIDEO_TS/VIDEO_TS.BUP failed
libdvdread: Can't open file VIDEO_TS.IFO.
libdvdnav: vm: failed to read VIDEO_TS.IFO
libdvdread: Using libdvdcss version 1.2.10 for DVD access
libdvdnav:DVDOpenFileUDF:UDFFindFile /VIDEO_TS/VIDEO_TS.IFO failed
libdvdnav:DVDOpenFileUDF:UDFFindFile /VIDEO_TS/VIDEO_TS.BUP failed
libdvdread: Can't open file VIDEO_TS.IFO.

But why UDF? What if DVD has a different file system? Because when I insert an another DVD with UDF — it works fine.

So, this DVD doesn't work (dmesg output):
ISO 9660 Extensions: Microsoft Joliet Level 3
ISO 9660 Extensions: RRIP_1991A
But this works fine:
UDF-fs: Partition marked readonly; forcing readonly mount
UDF-fs INFO UDF: Mounting volume 'DVD', timestamp 2007/07/26 19:01 (10b4)

Maybe this is still a bug in libdvdnav?

And an another moment. If I will rip DVD in ISO 9660 (that didn't worked from the optical disc) onto my hard drive — it works fine too.

P.S. Yes, my user is in the optical group.

no idea but this is clearly not a bug in vlc