OK, time for another experiment, if you are up to it.

I want you to install a test Sony driver that sorts the database records in title order.
What you do is:
1) find your calibre installation directory. It should be c:\program files\calibre2.
2) In that directory, you should be able to navigate to Lib\site-packages\calibre\devices\prs505
3) In the prs505 directory, you should see the file sony_cache.pyo.
Continue only if you have found the file sony_cache.pyo
4) Ensure calibre is not running.
5) rename sony_cache.pyo to sony_cache.pyo.save.
6) Download the attached file sony_cache.zip. Extract the file sony_cache.py from the zip file, and copy the .py file to the folder now containing sony_cache.pyo.save.
7) Start calibre, connect your device, let it update metadata, then check if the order of books in the author list has changed. I hope so.
8) for completeness, post the cache.xml file so I can verify that the sort-by-title worked.
9) now, or certainly before upgrading, delete the file sony_cache.py and rename the file sony_cache.pyo.save back to sony_cache.pyo.
Thanks again!