Well, it seems like I have a workaround that works for this particular installation, probably for other installations too.
In a fresh installation of Jaunty, sound works for all users, including those that reside on the LDAP tree. It seems that sound for LDAP users goes with some particular update. I rememberd that one of the upgrades included PulseAudio, so I decided to do a fresh installation and then upgrade everything but PulseAudio. In this installation there is barely anything stored on the local hard disks, nearly all is stored on the server because all files that are worked on must be shared. So, easy, repartition the hard disks and reinstall the OS from scratch, there are almost no local files to backup. Then do all the upgrades ***EXCEPT*** PulseAudio, and disable upgrades. Reconfigure Samba and PAM to fetch users from the LDAP server. And all working. Then restored Evolution config (what a useful feature!), reinstalled the accounting software (simple double-click on a .deb file) and Skype, "et voilą". Apartment management software (they rent apartments) is just a set of PHP scripts on a server declared as a VirtualHost (works as a website) so nothing to install on workstations.
I would not call this a solution, it is tedious and lengthy, but it works. I wonder what will happen when the time comes to upgrade to Ubuntu 9.10.
And I leave a though to share with you. It is hard to make companies move to Linux. When they do, it's because they trust me and I must not leave them down. When I face situations like this, it makes me utter quite a few curses. I don't know who in Canonical (or wherever else) has coded an upgrade that left LDAP users without any sound, but:
1) This person definetely did not think of corporate users. What other surprises can I have if Canonical thinks of private users only? I am very upset.
2) If I met this person I'd have a word or two to say. Polite, but concise.
Last edited by awe; 3rd September 2009 at 12:28.