I've never used so much inetd so I'm not sure I understand what happens
Looking at this file it seems somebody played with it? You?
#<ftp-off>#ftp stream tcp nowait root /usr/sbin/tcpd /usr/sbin/proftpd
#ftp stream tcp nowait root /usr/sbin/tcpd /usr/sbin/wu-ftpd -l
check that either /usr/sbin/proftpd or /usr/sbin/wu-ftpd exist and uncomment the one.
then killall -HUP inetd to restart inetd
or reboot the server or restart inetd
did you check that the server doesnt have an xinetd? (replacement for inetd). The ftp client will NOT use (x)inetd so don't bother to look at it on the ftpclient
Sorry I have to leave, hope somebody will help you