asterisk users - Dec 2011 - [hint state][BLF] Asterisk 1.8.7 does not send RINGING notifications, even with notifyringing=yes

Hi,
I set verbose to 3, but I do not see any RINGING notification in the 
CLI. On the contrary, when the phone goes UNREACHABLE I get:

[Dec 13 21:10:06] NOTICE[9988]: chan_sip.c:25533 sip_poke_noanswer: Peer 
'152' is now UNREACHABLE! Last qualify: 130
== Extension Changed 152[blf] new state Unavailable for Notify User 154
[Dec 13 21:11:08] NOTICE[9988]: chan_sip.c:20196 
handle_response_peerpoke: Peer '152' is now Reachable. (528ms / 2000ms)
== Extension Changed 152[blf] new state Idle for Notify User 154

If I manually set the state to RINGING using 
Set(DEVICE_STATE(SIP/152)=RINGING) I get:

Extension Changed 152[blf] new state Ringing for Notify User 154

but otherwise I don't get any ringing notification.

Cheers,
Niccol?