Hello !
Nokia E60 (SIP client) firmware 1.x.x.x is working with Asterisk.
Firmware 3.x.x.x register with Asterisk, but is not working, incoming/outgoing calls 
There is no way of downgrade the firmware, so i’m stuck
Any solution ?
please explain “not working” and provide some logs
The good news: YES it IS working
The bad news: not without deleting the SIP settings and punching them in from scratch (for me anyway). I was updating from 2.x but at least give it a shot.