TELECOM 247

I have a Toshiba DK280 system.

One (and only one) of our digital extensions is exhibiting a problem
whereby when a call is in progress, an incoming call (which would
normally ring on that extension) causes a tone to be heard not only by
the user of that extension, but by the other party.

Ive looked in Program 35 (Station class of service) at Busy Station
Ringing, but that wasnt it (or atleast that wasnt set)

Anyone with roshiba programming experience have any ideas at what else I
should look at?

Regards,
Jim