I have just tested with a newly converted "The Middle Temple Murder".
I did about 40-50 random highlights. At no time did I see an non-marked space in the middle of the highlight! Neither did I get the not underlined part of a highlight!
It may be simply random and I happened to choose areas in other ways, but it sure looks like what you did had an effect. Thanks Joel!
I did have some "not sticking" highlights.
The first was when I marked a complete page. Other complete pages worked fine.
The other is this:
Code:
<div class="calibre">
<span class="koboSpan" id="kobo.76.1"> "Well, we may find out something about this scrap of paper," he observed.</span> <span class="koboSpan" id="kobo.76.2">And he waved a signal to the nearest taxi-cab driver.</span>
</div>
<p class="calibre" style="margin:0pt; border:0pt; height:1em"> </p>
<div class="mbp_pagebreak" id="calibre_pb_6"></div>
</body>
</html>
If I mark, say "he waved a signal to the nearest taxi-cab driver." it works.
If I mark beyond the ".", it doesn't.
Hmm, I just got a mark with missing underline. I marked from the last "." back up to "Rathbury" and most of the markings were not highlighted (and it didn't stick). I tried to replicate it a couple of times, but those tests all showed all underline.