Both fields are ok. in admincp there's full path from root to phpadsnew dir.
On config.inc.php there's full URI for phpadsnew.
My filesystem is like this:
/ (ftproot)wwwhtdocs
forumhtdocsadv
on forum.dmn.tld is called /adv and it's ok.
on
www.dmn.tld is called also /adv but there isnt' any dir here.
So I solved for now with a symlink called
/adv but I feel like a dirty hack.