SuSEfirewall & portscan

Hi all, Probably asked a few times on this list but don't shoot me. I have the SuSEfirewall up and running and closed everything FW_SERVICES_EXTERNAL_TCP & UDP = "" and also INCOMING_HIGHPORTS_TCP & UDP = "". A portscan (nmap) however reveals that all the upd ports are open! Is this a risk or not and how are these closed with the help of the script? Thank you, -Peter-