[bj1947]

HOWEVER, after reading some very good advice in the forum discussion about this, I was able to resolve the problem for myself. I REMOVED the latest Calibre update and re-installed Calibre version 1.71. Then I opened the Settings page and unchecked a box in the "Automatic Updates" section so that my Calibre does NOT automatically update to the newest version.

I can bring Kindle ebooks over from the "My Kindle Content" folder to Calibre, and it does convert them to EPUB & AZW3 formats (the newer version of Mobi format), and I'm satisfied with that. I don't read books in my Kindle Fire (regardless of how "convenient" Amazon.com says that is). I read epubs on my PC ... but what is important to me is that I can use Calibre to catalogue my books by content area, by author, and by other descriptors I use. I prefer to maintain control over my books this way. I resent the interference of any commercial service that presumes to hold ownership and control over products that I purchase. Amazon is one of those. They are not a publishing house, they are a warehouse distributor. I understand the copyright infringement laws. I'm not selling, copying or giving out unauthorized copies of my books. I'm just managing my content, and this solution works for me. Thanks for all your suggestions. Yes, the KFX DRM incription mechanism is formidable, but where there is a will, there is always some way to prevail.