Here are some tidbits other customers of EccoNote Pro have found useful:

If you have a corrupted sound file (a file that says it has a file size, but won’t play in iTunes?).  You might try a program like BlackLine.  It can help in repairing audio files.  Here’s the current like that we have:  http://www.macupdate.com/app/mac/30370/backline

Corrupted Sound File (Mac Only Solution)