I'm not sure if this a well known phenomenon but site map generators and presumably bots don't seem to follow hot spot links. I had to add additional links on the page for the site to be mapped correctly.
HotSpot links created by Dynamic HTML Editor are simple transparent images with a link so perfectly indexed by search engines bots (like other picture or shapes with a link created into your pages) Image maps can create problems for poor bots.
>I had to add additional links on the page for the site to be mapped correctly. Strange, maybe your site map generator ignores links on pictures?