xfce4-mixer-plugin uses a whole CPU core

[Forest]

After I've been logged in for a while, the gnome system monitor shows xfce4-mixer-plugin using 100% of a CPU's cycles. I have a dual core system, so the UI remains responsive, but I think it's safe to assume that this is a bug of some kind. Removing the mixer from the xfce panel and re-adding it gets rid of the problem temporarily, but it resurfaces next time I reboot.

$ lsb_release -rd
Description: Ubuntu 9.04
Release: 9.04

$ apt-cache policy xfce4-mixer
xfce4-mixer:
  Installed: 1:4.6.0-1ubuntu2
  Candidate: 1:4.6.0-1ubuntu2
  Version table:
 *** 1:4.6.0-1ubuntu2 0
        500 http://us.archive.ubuntu.com jaunty/universe Packages
        100 /var/lib/dpkg/status

[Alberto Moreno (albertomm)]

I can confirm this bug on Karmic Koala.

Description: Ubuntu 9.10
Release: 9.10

xfce4-mixer:
  Installed: 1:4.6.1-2ubuntu1
  Candidate: 1:4.6.1-2ubuntu1
  Version table:
 *** 1:4.6.1-2ubuntu1 0
        500 http://es.archive.ubuntu.com karmic/universe Packages
        100 /var/lib/dpkg/status

[Rena Kunisaki (i-am-inuyasha)]

Same here, except not quite 100%. I have Xubuntu 9.04 on 32-bit x86 and occasionally, xfce4-mixer-plugin starts using 80-90% CPU. If I have an instance of xfce4-mixer itself running, that is not affected, nor does it seem to have any effect on the bug.

I am using ALSA on a C-Media CMI8738. The bug is fairly rare and I can't tell just what triggers it. In this particular case, it happened right around the same time I suddenly lost network connectivity - I'm not certain whether that was an issue with the machine or the router. Just stopped being able to ping it at all for a few minutes. Likely a coincidence, unless anyone else has noticed a similar pattern.

[cmeerw (cmeerw)]

I am also seeing this bug on Karmic (essentially every time I unplug my USB headset).
BTW, the root cause appears to be the same as Bug #417778 (https://bugs.launchpad.net/ubuntu/+source/xfce4-volumed/+bug/417778)

[Charlie Kravetz (cjkgeek)]

Thank you for helping improve Xubuntu. A great help from cmeerw, I am marking this bug as a duplicate of bug 417778. Since the root causes are the same, they are duplicates.