larryy, the reason is not the update. Your kindle's internal clock probably reset itself back to Jan 1, 1980 or so. I had that happen. The list is sorted by dates the books were accessed last. And when you open a book now it was accessed last in 1980, but the books you opened before have a date of October 2009.
If you have whispernet reception your clock should reset itself. I have a non-international kindle and live in Germany - I had to use the USB Networking hack to access the kindle from the Computer and set the clock. See
https://www.mobileread.com/forums/sho...068#post617068 and this post for how to change the clock:
https://www.mobileread.com/forums/sho...AAA#post514405