I'm for a site where I can download old versions of DVD Decryptor. If anyone out there has 3.5.1. please send me a private message, so I can give you my email address to send it over. Thanks.
Don't know why you want to use an older version. You would get better results (bug fixes, ARccOS, better decryption methods, etc.) with version 3.5.4.0 or better rather than 3.1.5.0 If you insist: http://www.agrreviews.com/modules/mydownloads/sf-17394-DVD Decrypter 3.5.1.0.html