This appears to be caused by having a clearing div element outside of the for loop in the album template. Which is absurd. The following album template structure gave me double-vision:
<div id="ngg-album">
<? foreach($galleries as $g) { ?>
// blah blah blah
<? } ?>
<div class="clear"> </div>
</div>
If I remove the clearing div or change it to a <p>, it works as intended.
-jd
