I had the same problem and resolved installing k3b. I think this error
occurs because missing plugins. Try to emerge k3b but check flags before.

2007/9/18, Mark Knecht <markknecht@gmail.com>:
>
> Hi,
>   Message is to Randy and others that have been helping me with my
> audio problems with xine. This evening I discovered the root cause of
> the problem of no sound when playing DVDs in xine. Unfortunately I
> don't have a good solution yet. Maybe someone knows how to fix this at
> the command line?
>
>   OK, xine does produce sound, but this machine has  multiple sound
> cards and it's choosing the one that goes to the home theater system,
> not the PC's sound card:
>
> mark@dragonfly ~ $ cat /proc/asound/cards
> 0 [ICH5           ]: ICH4 - Intel ICH5
>                      Intel ICH5 with ALC655 at 0xfa081000, irq 21
> 1 [default        ]: USB-Audio - USB Audio CODEC
>                      Burr-Brown from TI               USB Audio CODEC
> at usb-0000:00:1d.1-1, full s
> mark@dragonfly ~ $
>
>   When I thought of this possibility I turned on the HT receiver,
> switched to the correct input and low and behold DVD audio was
> playing. Didn't test to see if it's 5.1. The HT receiver is hooked to
> the USB device which seems to be marked as 'default'. However hardware
> setup hasn't changed and earlier versions of xine went to the internal
> card so something has changed.
>
>   I don't see anything in /etc/modules.d/alsa that defines the second
> card as default. Does anyone know how Alsa does that?
>
>   It's possible that Alsa getting too cleaver by half and somehow
> 'deciding' that the USB interface is more suited to doing 5.1 than the
> internal card. If it is then shame on it I say. ;-)
>
>   Two potential solutions come to mind:
>
> 1) At the xine command line tell it which card to use. I'm looking
> through the xine --help listing but heck if I see how to do that.
>
> 2) Somehow tell also to make card 0 default and see if that fixes the
> problem.
>
>   Anyway, so the problem is partially solved. I can go the xine-users
> list and see if anyone there has a quick fix for this. At least it's
> starting to make some sense.
>
>   Thanks in advance for any ideas.
>
> Cheers,
> Mark
>
> # Alsa 0.9.X kernel modules' configuration file.
> # $Header: /var/cvsroot/gentoo-x86/media-sound/alsa-utils/files/alsa-
> modules.conf-rc,v
> 1.4 2004/11/16 01:31:22 eradicator Exp $
>
> # ALSA portion
> alias char-major-116 snd
> # OSS/Free portion
> alias char-major-14 soundcore
>
> ##
> ## IMPORTANT:
> ## You need to customise this section for your specific sound card(s)
> ## and then run `update-modules' command.
> ## Read alsa-driver's INSTALL file in /usr/share/doc for more info.
> ##
> ##  ALSA portion
> alias snd-card-0 snd-intel8x0
> options snd-intel8x0 index=0
>
> alias snd-card-1 snd-usb-audio
> options snd-usb-audio index=1
>
> ##  OSS/Free portion
> alias sound-slot-0 snd-card-0
> alias sound-slot-1 snd-card-1
> ##
>
> # OSS/Free portion - card #1
> alias sound-service-0-0 snd-mixer-oss
> alias sound-service-0-1 snd-seq-oss
> alias sound-service-0-3 snd-pcm-oss
> alias sound-service-0-8 snd-seq-oss
> alias sound-service-0-12 snd-pcm-oss
> ##  OSS/Free portion - card #2
> alias sound-service-1-0 snd-mixer-oss
> alias sound-service-1-3 snd-pcm-oss
> alias sound-service-1-12 snd-pcm-oss
>
> alias /dev/mixer snd-mixer-oss
> alias /dev/dsp snd-pcm-oss
> alias /dev/midi snd-seq-oss
>
> # Set this to the correct number of cards.
> options snd cards_limit=2
> --
> gentoo-user@gentoo.org mailing list
>
>