CMS Made Simple Forums

I selected a page to use as default detail page for the news module (2.11.2). that works well. now i want another category to display in a different page. i did:
but news items still open the detailpage i set up in news - options. i thought the above line would overwrite my default selection, no?

i removed my custom news_url and then it works. I still dont know whether this effect was expected or not. the detailpage id is part of the URL path, but not when news_url is set.
so not really solved, only fudged.
mario