Foyles UK, and Amazon ES/IT
Foyles has completely changed their site, so the current Foyles store plugin does not work. This will be fixed in the next calibre release (0.8.59).
Regarding Amazon Italy and Spain: could someone tell me if the store plugins are working? By "working" I mean that you can search for, find, and buy books. I can't test them much because one must "live" in one of the two countries before searching the site will work. My assumption has been that the sites work in the same way as the FR, DE, and UK sites, and it would be nice to know if my assumption is correct. Thank you.