The search result page uses a wrong path for the css files.
This is, because the search plugin provides $config{cgiurl} as basepath to the misc template. And so the path to the css files ends up to be "$config{cgiurl}/local.css". But this is wrong if $config{cgiurl} is not the same as $config{url}.
Maybe misctemplate() and misc.tmpl should use an additional variable which points always to the base of the wiki.
e.g. use "wikibase" for css and favicon and "baseurl" for the <base> tag.
thanks for pointing this bug out, I've fixed it --Joey.