asterisk users - Nov 2004 - Trouble-shooting SIP/2.0 482 Loop Detected

Could anyone outline a method for trouble-shooting these messages
"SIP/2.0 482 Loop Detected" I'm seeing on a particular peer?
There is no call going on when these pop up.

Sip read:
SIP/2.0 482 Loop Detected
Via: SIP/2.0/UDP 207.149.XX.XX:5060;branch=z9hG4bK0a322471
From: "asterisk" <sip:asterisk@207.149.241.3>;tag=as395506d6
To: <sip:217.10.79.219>;tag=019efdbfb68dd123f382ae5ce73ea92d.97e1
Call-ID: 2a91e30c4fd13ea93268f22f07f40584@207.149.XX.XX
CSeq: 102 OPTIONS
Server: sipgate ser
Content-Length: 0
Warning: 392 217.10.79.219:5060 "Noisy feedback tells:  pid=1922
req_src_ip=207.149.XX.XX req_src_port=5060 in_uri=sip:217.10.79.219
out_uri=sip:217.10.79.219 via_cnt==1"

Thanks,
--Ben Kirkpatrick

register => 5550000:DSLJFDSS@sipgate.co.uk/99
; 99 is local attendent

[sipgate.co.uk]
type=friend
username=5550000
secret=DSLJFDSS
host=sipgate.co.uk
fromuser=5550000
canreinvite=no
qualify=yes
insecure=very
context=level-one