Yast has gone nutz

Been trying to get the installation source going I tried selecting DVD and now I get this: Error Unable to create installation source from URL 'dvd:///'. Details: ERROR(Media:mount failed). Ok I selected /dev/dvd, not dvd:///. Where can I manually edit the file yast 'change installation source' from? Its obviously got a bad url there. This worked before I went to NFS. Many thanks, Matt