I'm change this in my privat copy in file 'print_all_bug_page_word.php' (diff output):

113c113
<

<div style="margin-bottom: 10px; <?php if($j>0) echo "page-break-before: always;" ?>">
475c475
< echo '

';

echo '</div>';

its work fine.
I will hope, this changes will assign to future versions of mantis.