Hi Rob and thanks for your help.
I have already checked xine.conf and settings are like yours.
I also tried to take down all pluto stuff and start xine from command line.
The result is that video is played, but no audio.
Then I rebooted my box, and during reboot I noticed the following error:
alsactl: set_control:909: failed to obtain info for control #50 No such file or directory)
So IMHO there is also an issue related to alsa.
I tried to issue
alsactl store
in order to rebuild /var/lib/alsa/asound.state and then rebooted again.
The previous error during boot has disappeared, nevertheless in xine device log nothing has changed and I'm still not able to play anything.
Just to add more info, the day before yesterday I made some tests recompiling kernel and modules. AFAIK this should not affect any particular device, as long as the proper kernel - modules set is loaded.
In fact here modules appears to load properly, just conf data are wrong and this sounds strange.
I'm going to reboot my box with knoppix, just to make sure that hardware is not faulty.
Has anyone some hints form me?
TIA
Marco