I managed to fix this. Not sure if this is “optimal” for others, and I think it only works with static images (not background images) but posted here in case it is useful for others. Perhaps an “official” version will come out later.
In the isotopic.php file (which should be put in your wp-content/themes/your-theme-name/asp/isotopic.php folder)
you want to replace these lines:
[html]<div class=’asp_item_img’ imgsrc=’<?php echo $r->image; ?>’ style="background-image: url(‘<?php echo $r->image; ?>’);">
<a>link; ?>’<?php echo ($s_options[‘results_click_blank’])?" target=’_blank’":""; ?>></a>
</div> [/html]
with these lines:
[html]<div class=’asp_item_img’>
<a>link; ?>’<?php echo ($s_options[‘results_click_blank’])?" target=’_blank’":""; ?>><img />image; ?>’ /></a>
</div>[/html]