64bit unclean?

[scruffy]

Ok, something's a problem:

>ebook-meta "Book Title - Author Name.pdf"
Title               : Author Name
Author(s)           : Book Title

(yes, it's reversed, this is one reason I wanted to automate this...
also, I have books not imported into Calibre yet, with no meta info but correct titles, and I wanted to make it easier both for importing and other meta usages)

>ebook-meta "Book Title - Author Name.pdf" -a "Author Name"

Original metadata::
Title               : Author Name
Author(s)           : Book Title

Changed metadata::
u'\tTitle               : Author Nam\uf256\n\tAuthor(s)           : Author  Nam\uf256'

Hmm, weird, ok, maybe it's a command line issue...

>ebook-meta "Book Title - Author Name.pdf" --to-opf=test.opf
u'\tTitle               : Author Nam\uf256\n\tAuthor(s)           : Author  Nam\uf256'
OPF created in test.opf

Ok, edit opf file, fix the bad info... and now use it...

>ebook-meta "Book Title - Author Name.pdf" --from-opf=test.opf
Original metadata::
u'\tTitle               : Author Nam\uf256\n\tAuthor(s)           : Author  Nam\uf256'

Changed metadata::
u'\tTitle               : Book Titl\uef6e\n\tAuthor(s)           : Author Nam\uef78\n\tBook Producer       : calibre (0.6.34) [http://calibre.kovidgoyal.ne
t\ub542'

Ok, try again, exact same opf file:

>ebook-meta "Book Title - Author Name.pdf" --from-opf=test.opf
Original metadata::
u'\tTitle               : Book Titl\uef6e\n\tAuthor(s)           : Author Nam\uef78\n\t

Changed metadata::
u'\tTitle               : Book Titl\uab73\n\tAuthor(s)           : Author Nam\uab65\n\tBook Producer       : calibre (0.6.34) [http://calibre.kovidgoyal.ne
t\u0385'

Ideas? This is Windows 7 64bit Home Premium. Looks like a problem on the last character in each entry... (filename/author/title changed to protect the innocent)

Unicode? UTF issues? 64bit issue?

Added to trac: http://bugs.calibre-ebook.com/ticket/4599

Kovid pointed out it's a duplication of http://bugs.calibre-ebook.com/ticket/4378

Followup: the file in question had an empty password, but a password nonetheless.
Something to look out for... removing password, the metadata worked fine. Not 64bit or unicode issue, this is a bug due to password protection weirdness.