I don't see what xfce4-mixer can do about that, please report a bug against xfce4-volumed at https://launchpad.net/xfce4-volumed . With version 4.9.0 the xfce4-mixer panel plugin can handle the keyboard shortcuts itself, you might want to try if that works for you.

you don't understand.

xfce4-mixer should catch volume changes from alsa.

actually I didn't use xfce4-mixer for awhile because of this stupid behavior. maybe its already fixed

(In reply to comment #2)
> you don't understand.
> 
> xfce4-mixer should catch volume changes from alsa.
> 
> actually I didn't use xfce4-mixer for awhile because of this stupid
> behavior. maybe its already fixed

Well that was not entirely clear from your report. Could it simply be that xfce4-volumed and the panel plugin manipulate different tracks? Can you please try to reproduce this with version 4.9.0 by first enabling the runtime debug mode as follows:

xfce4-panel -q
export PANEL_DEBUG=xfce4-mixer-plugin
xfce4-panel

and then manipulating the volume of the track that panel plugin is configured to use via alsamixer or xfce4-mixer. Each time you change the volume of that track you should see a message like

(wrapper:4485): xfce4-mixer-plugin-DEBUG: [xfce-mixer-plugin.c:975 xfce_mixer_plugin_bus_message]: received 'volume-changed' message from gstreamer

and the volume should change accordingly.

just tested again. everything seems to work fine =)
so either fixed or I did something wrong before