Hallo!
I dont't not what was the cause but when I search for a word or a phrase this word or phrase gets no no red highlighting in the results. I compared the source of the search result page on my wiki (unfortanetly a closed corporate wiki - so I can't give a link) and wikipedia and found that my results are not surrounded by <span class="searchmatch"> PHRASE </span>. Can someone imagine why?
I use MediaWiki 1.13.0 and the following extensions: BreadCrumbs, CategoryTree, CharInsert, Cite, Inputbox, ParserFunctions, SyntaxHighlight, Gadgets (Version r39580).
Thanks in advance!