I used Calibre intensively for a month or two, about a year ago, with no problems at all. However at present I am plagued by the following problem (I'm running Calibre 2.81.0 under Leap 42.2, on two different machines). Using the built-in editor I may spend hours editing the xhtml files, saving them regularly of course (I also keep backups). Of course I also use the editor's "Save" after about every three seconds. The bizarre thing is this: that having shut down Calibre, the next time I open it up it's as if I had never made those changes. Somehow Calibre (and/or it's editor) is pulling in the wrong files. This has been going on for weeks, and the only way around it I've been able to concoct is to (1) "Save as" from within the editor to a location and with a name that is unambiguously recognizable; then (2) close Calibre; (3) restart Calibre; (4) add the book I've just saved, tolerating the message that I've just created a duplicate; and (4) delete the previous one.

It appears that one needs to be a Ubuntu person to hook into the Calibre bugs discussion at https://calibre-ebook.com/bugs, so I've brought this up here. Has anyone else had this experience? Is it a problem specific to openSuSe? Thanks.