I did notice that the midi rendering that precedes the wav render yields a file with 0K size.....could be this.
Larry,
I don't know of any midi rendering that precedes audio rendering. Could you elaborate a little more on what you see that leads you to this conclusion. I'd like to give what you are doing a test run.
If I recall correctly, you are using the below option to render am I right?
Regards,
Noel