Ok so can you please try the following in TPortal.php in the two locations where we use readmore my copy of TPortal.php is so edited from this that I can't give you a line number.
$row['body'] .= '... <p><strong>'.$smcFunc['htmlspecialchars']('<a href="'. $scripturl. '?topic='. $row['id']. '">'. $txt['tp-readmore']. '</a>').'</strong></p>';
This gets around the bug....rather than actually solving it.