Update 3:
It looks like Calibre Editor doesn't like my RE -
Sigil runs it with no problem.
The RE engine goes to an endless loop (rather than freezes) if there are more than 2 tags like:
Code:
<p id="filepos2207" class="calibre1"><span class="calibre2"><span class="bold">Chapter One</span></span></p>
but it doesn't have a problem with this:
Code:
<p class="PCurrentAndTimesNewRomanAnd10ptAndCentreAlignmentAndLeftIndentAndRightIndentAndSpacingAfter"><span><span class="calibre18">Chapter 8</span></span></p>
