The current node.tpl.php does not check for empty $submitted and $terms variables.
The code:
<table class="nodetitle">
<tr>
<td>
<h2 class="title"><a href="<?php print $node_url?>"><?php print $title?></a></h2>
<span class="submitted"><?php print $submitted?></span>
<span class="taxonomy"><?php print $terms?></span>
</td>
</tr>
</table>
Should be changed to:
<table class="nodetitle">
<tr>
<td>
<h2 class="title"><a href="<?php print $node_url?>"><?php print $title?></a></h2>
<?php if ($submitted) { ?><span class="submitted"><?php print $submitted?></span><?php }; ?>
<?php if ($terms) { ?><span class="taxonomy"><?php print $terms?></span><?php }; ?>
</td>
</tr>
</table>
This avoids an empty line which looks ugly sometimes.