As it is a daemon, there is no debug output on standard output. To get debugging output (for instance before submitting me a bug report !), update the lines in inetd.conf which launches ktalkd and kotalkd to be :
| talk dgram udp wait root /usr/sbin/tcpd /opt/kde/bin/kotalkd -d ntalk dgram udp wait root /usr/sbin/tcpd /opt/kde/bin/ktalkd -d | 
Then edit /etc/syslog.conf to add the following line :
| *.* /var/log/all_messages | 
To make it work, you then have to restart inetd and syslogd :
| % killall -HUP inetd % killall -HUP syslogd | 
When submitting a bug report, never forget to include the debugging output, but also ktalkd's version number and the "./configure" output. Thanks.