Articulate Problem: Audio Missing

I have a serious problem with Articulate’13 and the time is so tight, please help me solve this. I had recorded my audio files, then 2 days later, I went into my powerpoint file to change “sync animations”, and no audio played. So I went to the Audio Editor and Record Narration, but all of my audio files are missing. I searched the forum and found this article - http://www.articulate.com/support/presenter-09/audio-is-missing-or-lost-in-published-presenter-09-presentation. I know that article for Articulate’09, but I have similar problem. I went through all the steps in that, but none of them applied to my situation. I don’t have time to make a diffirent e-learing lesson, and I am concerned this will happen again. Any ideas on why this happen, what can I do to  restore my audio files and prevent them on happening again in the future?

I am working on hard drive, not on network drive. I don’t have <presentation>old.ppta file in my folder.

I am confused and concerned. I appreciate if you can rely as soon as possible.

Thanks for your help.