If you get the proof of your book back and notice the chapter headings start at different levels on your pages, then check the font of your peplum. Sound weird? It is.
Upon late night searching of my ms, I noticed the font of that backward 'p' changed from TIMES NEW ROMAN-22, to MYRIAD PRO-14. Once I manually changed all of them to match, wa-lah!, everything worked like a charm.
This is what I did. I highlighted on the peplum at the beginning of the chapter and changed the font style and size. Then I deleted the extra peplum that wouldn't highlight. (The one right before the chapter heading.) Then I entered another peplum and my pages all matched.
Also, sometimes I had to click on a peplum and go to my toolbar to 'remove line after spacing.'