I have two VigorPhone 350's in an office, both of them running the latest firmware : 12202.26.1.06

When the user on one of the phones needs to enter numbers on her keypad to access facilities on the number she has called, it works absolutely fine - she can hear the tones as she presses the keys, as can the IVR system at whatever company she has called.

The other extension doesn't do this - the user can hear the keypad tones absolutely fine, but the phone system at the other end does not. It's the same whatever company she calls with IVR

I've trawled the settings and cannot find anything for DTMF - anyone got any pointers??

Selection for DTMF will be in-band, outpband, SIPInfo etc... change that setting.

Thanks for the information, however both 'phones are identically configured - I've checked every menu and sub menu.

What am I missing?