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"
If your NCX file contains a navPoint similar to:
Code:
<navPoint id="navPoint-1" playOrder="1">
<navLabel>
<text>Chapter One</text>
</navLabel>
<content src="Text/some_file.html#Chapter1"/>
</navPoint>
Then the target html file needs to contain something like the following:
Code:
<a id="Chapter1"/><h1>Chapter 1</h1>
And not:
Code:
<h1><a id=”Chapter1”/>Chapter 1</h1>
or:
Code:
<h1 id="Chapter1">Chapter 1</h1>
The second two both run the risk of html code showing when following a link to "some_file.html#Chapter1" (including jumping from chapter to chapter using the arrow keys)