Don't know if this is of any help for you guys when debugging, and maybe there's nothing to do about it, but... When reproducing the error on another app of mine (basically the same app but in another language) xcode says this instead of the previous message:
*** Terminating app du to uncaught exception "NSInvalidArgumentException', reason:
'-[EAGLView reportLuaError:]: unrecognized selector sent to instance 0x1100c03610'
As before, all works fine when the mp3s are set to Never encrypt.