My Sipura 1001 does that when I have a message waiting. You can turn the reminder half-ring off in the configuration settings.>About once an hour, my Sipura 2002 rings just once. I >thought it might be >faulty, so I configured a second one, and it does the >same thing. I >updated the firmware to 3.1.5 and still have the same >problem. > >Anybody able to shed some light on the random ringing >problem? > > >Thanks.