Plugin Manager > Latests Posts > Edit that.

Replace your code with this:
$siteposts = $db->query_read("
SELECT thread.lastposter, thread.lastpost, thread.views, thread.open, thread.forumid, thread.replycount, thread.threadid, thread.pollid, thread.title, user.username, user.userid, user.usergroupid, IF(displaygroupid=0, user.usergroupid, displaygroupid) AS displaygroupid FROM thread as thread
LEFT JOIN user AS user ON (user.username = thread.lastposter) ORDER BY lastpost DESC LIMIT 0, 5");
while($latest = $db->fetch_array($siteposts))
{

$latest['title'] = str_replace($hidechar, " ", $latest['title']);

if (strlen($latest['title']) > 28)
{
$latest['title'] = substr($latest['title'], 0, 28) . '...';
}
else
{
$latest['title'] = $latest['title'];
}

$latest['title'] = htmlspecialchars($latest['title']);
$trans = array("&" => "&");
$latest['title'] = strtr($latest['title'], $trans);
$latest['replycount'] = number_format($latest['replycount']);
$lastest[musername] = fetch_musername($latest);
$lastest[musername] = $db->escape_string($lastest['musername']);
$date = date("g:i a",$latest['lastpost']);

$latest_posts .= "
<div style='padding: 4px; border-bottom: 1px dashed blue;' >
<div style='font-size: 11px;'>&bull; <a href='showthread.php?t=$latest[threadid]' title='$latest[title]' style='font-size: 10px;'><b>$latest[title]</b></a></div>
<div style='padding-top: 1px; padding-bottom: 1px;'><a href='member.php?u=$latest[userid]' style='font-size: 9px;'>Posted by $latest[musername]</a></div>
<div style='padding-top: 1px; padding-bottom: 2px; font-size: 7pt;'>
<span style='float: right;'>at $date</span>
<span> <font color='#8A478F'><b>$latest[replycount] replies</b></font></span>
</div>

</div>";
}
$db->free_result($siteposts);
Change what I wrote in red to what matches your skin.