The title is probably being taken from the FB2 metadata. See
wiki: FB2 for more information about FB2. The only tool I have used to produce FB2 is
Book Designer, but it isn't obvious to me how to change the title in BD.
Since FB2 is just XML (
Eng:FictionBook description), all you may need to do is open the .fb2 file using a plain text editor and add:
Code:
<book-title>Title Here</book-title>
to the <title-info> section (or add a <title-info> section if there is none).