How do I get Feed Aggregator blocks to display images?

On Ubersoft.net I use imagecache to make little thumbnails of my comics that update every time a comic is updated. I have used Views 2 and mediarss to create an RSS feed for each of these thumbnails.

On another site (which is not yet live) I used feed aggregator to import each of those feeds. My intent was to create blocks of each of those feeds that would essentially duplicate the feature on Ubersoft.net -- i.e., it would display thumbnails of each comic that would update as the comics were updated (with a slight delay).

The problem is that the blocks of each of the feeds do not display the thumbnail image. If you click on the "more" link you get sent to full aggregation which displays the thumbnail image with no problems. So my question is, how can I get the image to show up in the block?

I've already added the img tag to the feed aggregator settings area, but that has no noticeable effect whatsoever.

Any thoughts? If the default aggregator feed doesn't work, are there other modules that will? Barring that, is there a way to create a custom block that will display this feed correctly?