you will need to look at /etc/services and make sure there is a line like this:

swat 901/tcp # swat

and then edit /etc/inetd.conf

#<off># swat stream tcp nowait.400 root /usr/sbin/tcpd /usr/sbin/swat

and remove the #<off># so the line is:
swat stream tcp nowait.400 root /usr/sbin/tcpd /usr/sbin/swat

( if that still doesn't work change the /usr/sbin/tcpd in the above line to /usr/sbin/swat )

HTH

~rock