ICT Sustainability Book on Amazon.com

My book "ICT Sustainability: Assessment and Strategies for a Low Carbon Future" just became available on Amazon.com. But I was having trouble doing the page breaks using Calibre. Judging by the preview on Amazon, I have horizontal lines between the chapters, not a page break (I don't have an Amazon Kindle, PC or Apple Mac, to see it on). The ePub version looks much better.