Fantastic, Bob, thanks for your reply. I expected as much...
I found this googling:
Changed 3 weeks ago by kovidgoyal ¶
* status changed from new to closed
* resolution set to duplicate
This is a known bug. calibre doesn't support setting metadata in PDF files and some models/firmwre versions of the Sony reader always overwrite the calibre specified metadata in the database with the original PDF metadata. This wont be fixed until calibre gets the ability to write pdf metadata or SNY fixes their buggy firmware.
It's interesting because the tags actually went from my PDF collection in Calibre into the 505 without issue... I'm wondering if there is no way to get the PDF metadata across without actually renaming it in a way Sony likes.
I will experiment with some other PDF metadata editing. Hopefully there's a trick to get them across without having to reconvert it to another type of file.