OK, thanks for your response. Evidently you already changed the hanyuu reference to iqdb.org, so the major problem is gone.
However, the find similar link, e.g. on post #1130345, still only passes a relative URL:
http://danbooru.iqdb.org/db-search.php?url=/ssd/data/preview/10c80edfd5978f0e2f706f29224d2fd0.jpg
So iqdb has to guess which hostname has to be used to retrieve that image from. For now all relative URLs starting with "/ssd/" are guessed to be from Danbooru, but that's an ugly hack I'd like to remove.
You can also get rid of the db-search.php part since that's implied by the danbooru part of the hostname, so the actual find similar link should be like this:
http://danbooru.iqdb.org/?url=http://danbooru.donmai.us/ssd/data/preview/10c80edfd5978f0e2f706f29224d2fd0.jpg
