The new (updated and hopefully stable) distribution of files is located at the bottom of this post.
New in this release:
1) YouTube changed the encryption used on video signatures again, and this fix addresses that change. (Vevo and other similar channels were affected.)
Only YouTubeToMp3Converter.class.php was modified, and (since the last update) only code in the existing DecryptYouTubeCypher() method was updated.
I will soon be updating the paid-for version of the app as well, and I will email an updated (free) copy to all those who have already purchased the script. (Updates will be sent to your Tradebit
email addresses only.)
As always, please let me know if you have any questions/concerns regarding the above and/or the code.