you must be running on your SoundTest root folder to get access to the data/files. And Buffers must be .rewind()'ed before to reuse them after a put() or get() call. Either you can rewind all buffers or use the common Buffer.wrap(array[]) function.
I got your files and built a netbeans project which will run the test main() method, then you can here the sound playing.
Then I made the attached .rar, lwjgl jars and the di.wav data are missing so you must copy them into bin/ and data/ resp.