The only thing remotely like this I have heard of is "updatedtitle", see
Mobi2Mobi v0.13 - GUI for Mobiperl tools. So you may want to check all the metadata to see what is there (perhaps two author entries for example). Another possibility is that the "Book Type" is set incorrectly, see
Folders on Kindle, Calibre metadata question.
I think what I would do (just for these few ebooks) is convert the MOBI to ePub using Calibre's command line any2epub (specifying the author and title), and then back to MOBI using any2mobi.