Please can someone help urgently. My client needs to have a conference call in the morning and conferencing is not working! They are running the latest 3CX version 8 with a grandstream 4108 with the latest firmware. Connecting to the conference by dialling 700 works fine for internal extensions. If an external incoming call is transferred to the conference bridge they are able to dial the conference ID and press #. It tells them they are joining the conference, but at the prompt when it says "Press # to cancel or * to continue" NOTHING HAPPENS when either of these buttons are pressed. JUST SILENCE! This is incredibly frustrating!