In the past I was able to mute the incoming ringtone easily as follows:
This works fine for S60 3rd Edition devices (for the locales supported). For S60 5th Edition, and in particular the Nokia 5800 XpressMusic, the right hand softkey is now "Reject" and there is a new button (not a softkey) for "Silent".
key.iModifiers = 0;
key.iRepeats = 0;
key.iCode = aCode;
key.iScanCode = aScanCode;
Worse still is the fact that the Phone Client API is not present in the plugins for S60 5th Edition. So this is not an option either...
So, does anyone know of a way to mute the incoming call ringtone?