Originally Posted by sumpin
True, unless you then delete the copy from your original purchase and keep the copy managed by calibre. I never considered it an issue because the first thing I do when I purchase a book from Amazon, Barnes & Noble, or (as of a few weeks ago) Apple is to strip out the DRM so that everything in my calibre library is DRM-free.
I'll have a think on it and see if I can come up with a solution that does not require #4 but still allows one to have collections and content not managed by calibre live in peace with that managed by calibre.
OK, I understand it now.
I can live with this workflow, and I'll try to implement it...
Thanks for your support!