Originally Posted by PeterT
Step 1: Don't open the book in Calibre's eBook viewer.
Step 2: Use the Tweak Book Calibre plugin. Explode the book, then go into the META-INF directory and drop the calibre_bookmarks.txt file and then rebuild the book.
When I look in the META-INF folder, the only file is a single XML called 'container'. Has Calibre created a ghost in the machine?