Ignore missed calls on busy

[dvarella]

Hi guys,

I would like to know how to inhibits the phone to add an incoming call to the missed calls log (and display phone) if the user is in dialing state and denies an incoming call or on busy state (in call) ?
I tried this with T19P (firmware: 31.72.0.75) and T20P (firmware: 9.73.0.40), but no success.
Every time that someone calls me and I am on the phone, It is logged on the phone's display a missed call log.
I already tried to set "Waiting call" feature to "Disabled", but it didn't work.

Any idea ?

Thanks in advance.