I think that the problem seems to happen here, and is noted in the code:

em_manager_helper.php
lines 7252-7257

// Note, this will destroy embedded HTML in the equation (e.g. if it is a report)
// Should be possible to use jQuery to remove just the LEMtailoring span, but not easy since done (the following doesn't work)
// _tmpval = $('#question801 .em_equation').clone()
// $(_tmpval).find('[id^=LEMtailor]').each(function(){ $(this).replaceWith(function(){ $(this).contents; }); })
$relParts[] = " $('#" . substr($jsResultVar,1,-1) . "').val($.trim(LEMstrip_tags($('#question" . $arg['qid'] . " .em_equation').html())));\n";

No, nl2br from phpjs last version fix the issue.
http://phpjs.org/functions/nl2br/

Fix committed to master branch: http://bugs.limesurvey.org/plugin.php?page=Source/view&id=15067

Fix committed to 2.06 branch: http://bugs.limesurvey.org/plugin.php?page=Source/view&id=15068

Ah, yes, I see now. Thank you - it's fixed and my limited understanding of LS is improved to boot!

2.05+ Build 150508 released