Many thanks - all !
Diap, no, the pesky mbp's sit in my "Add" list, but I at least stopped meself from putting them into Calibre ! And I don't add from My K Content - I've only just discovered that exists ! But I'm reassured young Alf is innocent ....
However, perhaps Alex has an answer - I shall have a look this p.m. - fingies crossed, 'cos that sounds like "it was" , hidden.
And finally, DrOH - terrific, spot on ! Worked a treat

merci .
It's increasingly becoming a distinct possibility that I unknowingly (easy fo moi) or perhaps stupidly (more likely) hit the wrong button/s , possibly in the wrong sequence at the wrong time, perhaps en out of curiosity (more doubtful).
But I shall persevere, and follow all suggestions gratefully recieved.