I just stumbled upon something. Apparently, in the distribution DIR_CFG/core.cfg.php file DIR_SND is set to "sound", but the actual directory is named sounds.

If you have downloaded the first build, just open up DIR_CFG/core.cfg.php and look for this:

define(DIR_SND, "sound");

And change it to this:

define(DIR_SND, "sounds");

The default configuration file has been updated and will be included in the next release (which will take place this weekend).