[Freeswitch-users] DTMF not comming through on some calls

Hi, I have an urgent issue if anyone can help. I have been running freeswitch for 3-4 weeks now without issue. In the last 2 days some of the calls coming into the switch seem to get set up in such a way that means they cannot carry DTMF. ie on that call, no dtmf signals come through from the phone. It's not that digits get dropped some calls semm to handle dtmf perfectly and others don't seem to get dtmf at all. Can anyone shed any light opn this or suggest any solutions? Many thanks Andy