Grabbing at straws here but maybe someone has had experience with this. I am in the US and administer a Conference bridge for my company. When a conference is in progress and one of our UK employees tries to join using their blackberry they can't. The call to the bridge completes but after it completes the system does not see any DTMF tones which keeps the system from recognizing which conference they want to join and other authorization sequences that are used. Anyone have any ideas? I should mention the conference bridge is working via VIOP using SIP trunks to interface with our phone switch.