There is another, much more manual, method. It took me a while to find it. It allows you to export your bookmarks to, or import your bookmarks from, a desitination of your choice.
Bookmarks --> Manage Bookmarks --> File --> Export --> (save)
Bookmarks --> Manage Bookmarks --> File --> Import --> From File --> Next --> (open)
I'm currently using Mozback, too -- I just thought I'd mention this.