Thank you for your post.
Another person reported this problem, but I have not been able to duplicate the problem. Is it possible you can send me your bento.bentodb database file? I have sent you a private message (top of this page - right side - X Messages) with instructions where to send the file.
If you cannot send the file, then go into Bento and export to a CSV file. Then, within FileMaker Pro, import the CSV file.