[asterisk-r2] Sending DTMF 'f' ?

[Moises Silva]

Hum, I see what you mean. But, MFC and DTMF use different pair of
frequencies and F does not even exist in DTMF. Please enable dtmf
debugging in your logger.conf and try to reproduce, I'd expect to see
clearly if chan_dahdi/chan_zap is the one detecting a MF digit and
wrongly sending it down to the core as DTMF digit.

Did you patched that asterisk yourself?