Some of you may find that when you go from LTSP 4.1.1 to LTSP 4.2, sound either no longer works, or you have some clients that you know have drivers for Linux, but you still cannot get them going. Perhaps they are newer clients with newer sound drivers?
Part of the problem may be that LTSP 4.2 started pushing the 2.6 kernel back to the thin client, and while the 2.4 kernel used OSS drivers by default, the 2.6 kernel uses ALSA drivers. Thus, any manufacturer taking the time to write sound drivers for Linux today, will most likely produce only an ALSA driver and not an OSS one.
DOWNLOAD the latest LTSP-esd-alsa tarball package for Fedora 7 (tested).
Update: Here are some of the screenshots to edit the sound preferences to select the ESD sound daemon:
