It never stopped speaking for me. I just kept hitting keypad enter over and over, and if I timed it right, I could eventually get it to shut up. Have you tried turning the Dectalk off and back on at the point it hangs? It might be hanging because it's getting overloaded with all the speech coming in. In other words, it could be a handshaking issue. Lastly, have you tried loading the Dectalk module in one of your startup files? I don't know about other distributions of Linux, but Slackware has a file called /etc/rc.d/rc.local where you can put in special commands. Debian, IIRC has a file where you can list modules which should be loaded. Have you tried starting Speakup from one of these?
