[tomsem]

There seems to be some bug with saving or reading the 'accessed' time stamps (wherever Kindle keeps that info). I had one book which never moved to the top of 'most recent' order in a Collection that it was in, though some items were above and below it in accessed order (it did move up in the 'most recent' item list). Other books didn't have this problem.

I finally removed it from my Kindle and downloaded it again. That seems to have fixed it.