You need to add <? echo $image->filename ?> to the gallery.php file. probably about line 40 or so. I’ve modified mine a bit, but here’s how my code looks, to give you an idea on where it goes:
<?php foreach ( $images as $image ) : ?>
<div id="ngg-image-<?php echo $image->pid ?>" class="ngg-gallery-thumbnail-box" <?php echo $image->style ?> >
<div class="ngg-gallery-thumbnail" >
<a href="<?php echo $image->imageURL ?>" title="<?php echo $image->description ?>" <?php echo $image->thumbcode ?> >
<?php if ( !$image->hidden ) { ?>
<img title="<?php echo $image->alttext ?>" alt="<?php echo $image->alttext ?>" src="<?php echo $image->thumbnailURL ?>" <?php echo $image->size ?> />
<?php } ?>
</a><? echo $image->filename ?>
</div>
</div>
<?php if ( $image->hidden ) continue;
if ( $gallery->columns > 0 && ++$i % $gallery->columns == 0 ) {
print '<br style="clear: both" />';
}
endforeach; ?>
Also, you can try <?php var_dump($gallery) ?><?php var_dump($images) ?> to see everything you can access.
