A new (updated and hopefully stable) distribution of files is located at the bottom of this post.
New in this release:
1) Fixed a bug that periodically caused video downloads to fail on Windows and XAMPP platforms.
The existing YouTubeToMp3Converter.class.php file was modified, and only the SetFlvUrls() method was updated.
As always, please let me know if you have any questions/concerns regarding the above and/or the code.