you need to edit your /etc/services file. comment out the lines for the services that you don't want to run. a few that should be commented out:
rlogin
telnet (if you enabled ssh)
finger
ftp (unless you are running it..)
whod (whois server)
identd (unless you are using IRC, and need it..)
NIS/NFS (Unless you need them...)
RPC (You don't need it, trust me..)
Then reboot your box, and try port-scanning again.
SSH installed. How to disable rlogin? : disable, rlogin, debian