Text in web archives not highlighted

I just bought DT/DA Bundle and have a question I could not find an answer yet on the board:

When I search for certain words or phrases the text in text or RTF files gets highlighted in the preview window corrctly. But this does not work with html-Files or web archives. DT does find text in web archives which are in the data base, but the relating text is not highlighted. Any ideas? :confused: