gwilly, I have been installing Panasonic systems for years with no problems..
Yes Panasonic support is a joke but if you buy your phones from the right company you can get awesome support.. it also helps to go to training, that way the software makes sense.

sound.sd, if he made the conference call between both of the other parties and he was kicked off and the other 2 parties were still able to talk that means that the call, CO-CO was still there but his extension cut out. I see he is using the cordless phones, he isn't simply walking out of range of the receiver or have low batteries does he? Or is this happening on all of the phones? I would also look at call duration settings, I have had people have me set it sometimes to try to limit the amount of time that their kids are on the phone and they usually have me get rid of it a few days later.