Mrs_Often,
Thank you for your attachment, I'll certainly use that.
Due to an unexplained bout of blindness I never even noticed the "Filter Style Information" tab.

I guess I saw "CSS" and my brain filtered out any image from the immediate area (I'm allergic to CSS).
I was planning later to look into taking out all the constraints from my EPUBs and now I know how. Thank you.
As for the EPUB being at fault, I agree with that.
But still the point is that it should not crash.
If fonts or line spacing or margins are locked then I perfectly agree that the device should not be expected to alter them but nor should the device crash.
I now carry a paperclip with me...