My bad. Sorry about that.
I did it properly again: I saved the ePub as an html file, opened LO with my usual model, inserted the html file, and, indeed the images were here, in their right place.
Thinking about it, my mistake which made the images disappear comes probably because I was not careful enough and did not check that the odt file had been saved in a distinct directory.
OTOH, I never saw the Diap Dealer error message on Linux... Not everything is bad.
