[cisco-voip] SIP on Cisco 7960

[AKN]

I had SIP firmware 6.1 on my Cisco 7960.
It was working fine and I was able to register to my SIP provider and 
make calls.
Last week I tried to upgrade it to 7.5, and it went quite well and was 
working fine.

But to get familiar with the booting/initliazation/upgrading process I 
downgraded/upgraded it to 6.1 then to 6.3 and then to 7.5.

Suddenly I saw that the phone is not getting registered with my SIP 
provider. On capturing packets with Ethereal I found out that once my 
phone sends the REGISTER to SIP proxy, the SIP proxy returns 401 
unauthorised, but then instead of sending REGISTER again with the 
credentials my phone sends REGISTER with same as the first one without 
any credentials hence does not get registered. This is repeated all 
again and again.

Now I have checked with every firmware from 6.1 to 7.5 but the same 
problem persists. Also I have tried many different SIP accounts.

What you people suggest to solve this problem. Do any of you have 
encountered same problem before.

Thanks.

ajit.