Hi, I think what has happened is you bought the files using a Mac and stored them on a remote (non-mac) drive, but then when you open the files Jaikoz is not complaining about the music file itself but the OSX hidden file that should normally be hidden to the user.
i.e complaining about
._10 Baltihorse.m4a
not
10 Baltihorse.m4a
You get this problem if copy mac folders to a windows machine, I note that you are not actually using Windows but the problem is essentially the same and maybe to do with the format of your media folder.
So in summary nothing to worry about, but Jaikoz should be improved to silently ignore these hidden files.