[Asterisk-Users] SIP REGISTER -- Via 0.0.0.0:5060 -- Oooops?!

[Benjamin on Asterisk Mailing Lists]

On a newly built Asterisk 1.02 system I am getting a rather strange
SIP register message ...

REGISTER sip:ispvoip-9999.ocn.ne.jp SIP/2.0
Via: SIP/2.0/UDP 0.0.0.0:5060;branch=z9hG4bK3d1d0887

and further down ...

Contact: <sip:05012345678 at 0.0.0.0>
Event: registration

the register directive in sip.conf looks like this: 
register => 05012345678:passwd:AUTHUSR at ispvoip-9999.ocn.ne.jp/05012345678

What's this 0.0.0.0 address doing the SIP message? Is this another bug?

-- 
Sunrise Telephone Systems, 9F Shibuya Daikyo Bldg., 1-13-5 Shibuya,
Tokyo, Japan.

NB: Spam filters in place. Messages unrelated to the * mailing lists
may get trashed.