The Kobo started displaying a limited selection of the ebooks actually loaded by Calibre. Then the device showed multiple copies of ebooks I had removed - like 20 or more copies. Then the device showed multiple copies of something called Redemption and wouldn't open anything that was bookmarked before the pooch.
Well I tried removing the ebooks using windows explorer and then re-upgrading the Kobo device. I now have an empty Kobo. Unlike some, I want my 100 classics. I gave up and called support for Kobo. They are sending me an RMA package so that I can send them the device to fix or replace.