The above problem might be related to the following link which describes the updates incorporated into Calibre 0.8.60
http://mac.softpedia.com/progChangel...log-35818.html
"What's new in calibre 0.8.60:
July 13th, 2012 ...
Bugfixes:
Kobo driver: Do not perform write operations on the Kobo database if its version is newer than the latest version the driver supports, for safety"
Somewhat ironically, the error message is perhaps a new message that makes reference to this compatibility check, although in the two cases noted in my initial posting, Calibre still performs write operations to the Kobo database.
It might be useful if the Calibre error message made reference to what is the most recent version of the Kobo firmware that the updated Calibre software supports ... but does that mean that a new version of the Calibre software must be created and installed every time the Kobo firmware is updated ?