Originally Posted by hnoto
The metadata changes are in the Calibre files--which are all ok. (I did do a copy of all the folders over to my external HD last night, just in case.)
Not sure which files you are referring to here. If you are talking about the files in Calibre on your HD, then just copying them is not sufficient unless you also copy over the big metadata.db file that contains all the metadata. The better way to do it is to select all the files in Calibre then do a Save to Disk. This will also copy metadata into each individual folder. You can reimport those and all the tags will be there.
I don't think you had to delete all the files off the Sony. A simple reset works each time for me. After that, all my files and metadata are still there and it will work again with Calibre. If you do want to delete all the files again, there is a format disk option on the device itself that would be better. That will wipe the memory on the device.