SIP/2.0 489 Bad event

Asterisk can't handle NOTIFY messages from Linksys PAP2 devices. It returns:

<--- SIP read from 89.97.XX.XX:59020 --->
NOTIFY sip:62.94.XX.XXX SIP/2.0
v: SIP/2.0/UDP 192.168.2.102:5060;branch=z9hG4bK-f7b894ef
f: ras3 <sip:ras3@62.94.XX.XXX>;tag=1e740d0dce0f5256o0
t: <sip:62.94.XX.XXX>
i: 5553729-3a54ceea@192.168.2.102
CSeq: 1451 NOTIFY
Max-Forwards: 70
o: keep-alive
User-Agent: Linksys/PAP2T-5.1.6(LS)
l: 0

<------------->
--- (10 headers 0 lines) ---
CLI>
<--- Transmitting (no NAT) to 89.97.XX.XX:59020 --->
SIP/2.0 489 Bad event
Via: SIP/2.0/UDP 192.168.2.102:5060;branch=z9hG4bK-f7b894ef;received=89.97.XX.XX
From: ras3 <sip:ras3@62.94.XX.XXX>;tag=1e740d0dce0f5256o0
To: <sip:62.94.XX.XXX>;tag=as37825f1f
Call-ID: 5553729-3a54ceea@192.168.2.102
CSeq: 1451 NOTIFY
User-Agent: Asterisk PBX
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY
Supported: replaces
Content-Length: 0