Originally Posted by DiapDealer
There are ways to construct the source for your MOBIs so that you can drastically limit this behavoir. Namely: "Anchors Must Be Added Before Formatting Tags"
Wow. Thank you. That's fascinating and matches what little I know about Kindles and Mobi. Unfortunately since I am using Sigil to do all of my heavy lifting on the ToC and NCX file I don't think I will be able to code them that way. If I ever create something that really matters now I know what to do to fix it.
I'm guessing there is no way to tell Calibre to move the id's out from inside the h tags when it creates the mobi, is there?