can't create mcop directory / unable to play sound as another user

[edA-qa]

Binary package hint: mplayer

In the scenario where I use "su" to become a different user in KDE and then run "mplayer" to play a sound file (ogg in this case), I get the error:
   can't create mcop directory

If I manually add the directory beforehand </tmp/ksocket-username> then mplayer works*.

This bug may be actually a sound system bug and related to #55973, and possibly #42169. Though the scenario in which it appears is different. I additionally suspect it would apply to more than just mplayer (for instance Flash also has no sound unless I fix this, but I can't get error messages anywhere).

(*Note: I actually also need to give universal read/write to /dev/dsp to get this working in this scenario as well)

[edA-qa (eda-qa)]

Dapper: MPlayer 2:0.99+1.0pre7try2+cvs20060117-0ubuntu9 (C) 2000-2006 MPlayer Team

[Alex Mauer (hawke)]

Is this a duplicate of Bug #55973?