Ok, its been eleven days and many downloads with no further problems (fingers crossed). I have adopted two measures; one, I always use the software to eject the device and wait an extra thirty seconds or so before disconnecting the USB cord and two, I always eject the device and then reconnect before opening a different software application. ( Kobo desktop, Adobe Digital Editions, calibre, etc.)
I am relatively confident (although my fingers remain crossed) that this is the last post I will need to make on this subject.
