i've checked in mcc - i had slim, then
enlightenment -> mixer -> got sound cards | su -> exit -> mixer -> no sound cards
i've pushed my user in sudoers and this not changing anything (except that now i can sudo and this is not root-owning sound)
will try to use elsa
i've written pam_loginuid.so
got there system-auth (4 times), pam_nologin, pam_sonsole
also i usually got error after exiting enlightenment (failed to execute login command), maybe something stops to load config?
Steps to Reproduce:
and this works fine for openbox too
changing to lxdm with loginuid.so written in it makes no sense
"gksu terminology" does the same
to enable sound back i had to relog the session
"Root terminal" (konsole) makes sound unavailable too
there's a nice hack to run gksu (root terminal) once again, then sound cards becomes available, maybe it's a pam auth somehow...
does it work if you use another dm that slim ? like lighdm or gdm for example
bug is working with other dms
Slim is probably suffering the same problem (bug 11071) as lightdm was. I'll push updated slim to core/updates_testing with same fix.
Pushed new slim  to core/updates_testing. It should fix sound issues after using 'su' in terminal. Please test.
This is reproducible at least with xfce, maybe with other DEs too:
1. login with slim
2. play sound
3. use 'su'
4. try to play sound
5. update slim
7. start again with step 1
Testing complete on Mageia 3 i586 and x86_64. Advisory committed to svn.
Someone from the sysadmin team please push 11138.adv to updates.