I'm playing with demo IVR from FreeSwitch distribution and have a
problem with language settings. I would like to use Russian as a
default language for voice messages so I set in vars.xml

 <X-PRE-PROCESS cmd="set" data="default_language=ru"/>

and installed Russian sound files. It works almost correctly: all
phrases are played in Russian, but not explicitly specified .wav
files; say for

   <menu name="demo_ivr"
       invalid-sound="ivr/ivr-that_was_an_invalid_entry.wav"

I have

2009-12-14 22:17:57.506305 [ERR] mod_sndfile.c:194 Error Opening File
[/opt/freeswitch/sounds/en/us/callie/ivr/ivr-that_was_an_invalid_entry.wav]
[System error : No such file or directory.]

How to fix this and make it use the correct language?