Just installed the anniversary update. All seemed to go well. But every time I connect my Kindle to a USB port...
ETA: More oddities. On first launch calibre created a new metadata.db file. I needed to restore the original one to get my library back. Also calibre became the default application for handling zip files. Not happy.
ETA2: Other USB devices seem to work properly. Only the Kindle causes a crash.
ETA3: Was able to access the Kindle by rebooting with it already connected.