For the update that is.
It will be interesting to see if they (Amazon) back off this new "function" or admit to some sort of error or just stay silent.
Great to know you are already on it!
That was a long night trying to get all that back and I was wondering why it messed with most but not all.
I had just done (more or less) total reconfiguration for "collections" trying to make more sense of their wonderful menu system. Nothing to do with Calibre of course, laptop install still works like a charm. So your explanation makes sense of a very WTH just happened moment.