@jfm: Usually, each book has a clipping limit of 10%, which is usually sufficient. You can check the clipping limit of your book with
Java Mobi Metadata Editor.
Look for EXTH record
#401. If its value is significantly less than 10, the publisher might have made a mistake in producing the book.
When you buy your next Kindle book, you could use the Metadata editor to check for the presence of this record and delete it.