The handset is connected in the usual way (to the handset jack). The headset is connected to the headset jack. I am informed by Jabra and my own phone tech people that I have everything connected correctly.

The problem is that when the headset jack takes the phone "off hook" so that the headset can be used, the handset becomes "off hook" as well, and I end up getting sound coming out of both the headset and the handset. The only way around this that I've been told is to have a headset system whereby the handset isn't connected to the usual handset jack, but instead to a jack on the base of the headset. As I've said, that seems all kinds of wrong to me. Surely a headset jack, when put into operation, should not engage the handset.

Is this just a flaw with the Toshiba phone? I realize that this is a daughter card, and perhaps they couldn't disengage the handset without doing something more significant to the phone (such as cutting a wire, as newtecky mentions).

I guess another option would be to get a new phone that has a properly functioning headset jack. I dont know enough about our system to know which phones would work on it and whether any of them have proper headset jacks.