Asterisk 1.0.X SIP register to Asterisk 1.2.X

Asterisk Asterisk Support
1

Hi,

I have problemes connecting from an Asterisk 1.0.X Server via SIP to an Asterisk 1.2.X Server.
It seems that the 1.0.X Server sends a TAG-String in its register line.

Feb  6 09:15:57 NOTICE[18215]: chan_sip.c:10851 handle_request_register: Registration from '<sip:server2@sip.XXXXX.de>;tag=as7afcf5bf' failed for '195.XXX.XXX.XXX' - Wrong password
Transmitting (no NAT) to 195.XXX.XXX.XXX:5060:
SIP/2.0 403 Forbidden (Bad auth)
Via: SIP/2.0/UDP 195.XXX.XXX.XXX:5060;branch=z9hG4bK7438c664;received=195.XXX.XXX.XXX
From: <sip:cust1@sip.XXXXX.com>;tag=as6ae85e9c
To: <sip:cust1@sip.XXXXX.com>;tag=as3dc0691d
Call-ID: 55a5a59156514d8358be62f10f32eb1e@195.XXX.XXX.XXX
CSeq: 215 REGISTER
User-Agent: Asterisk PBX
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY
Contact: <sip:jobag@172.XXX.XXX.XXX>
Content-Length: 0

Anyone knows how to connect an Asterisk 1.0.X to an Asterisk 1.2.X without using IAX ?