[Asterisk-Users] 7960 backup proxy registration

[Michael Ulitskiy]

Hi,

I'm sorry to ask this question, but I thought I'd rather ask it here before
messing up with cisco.
Is anybody running cisco 7960 in redundant configuration? 
I mean I want the phone to be registered with both primary and
backup proxy (asterisks) so that service continues to work in case of primary
proxy failure. I've set in SIPDefault.cnt:

proxy1_address: 192.168.1.10
proxy1_port: 5060
proxy_backup: 192.168.1.12
proxy_backup_port: 5060

The problem is that 7960 registers all the configured lines with
primary proxy, but the line 1 only with backup proxy. It's not about registration
failure. The phone doesn't even try to register other 5 lines. As a result if the primary
proxy fails incoming calls work for the line 1 only.
Has anybody managed to register all the lines with backup proxy?
I'm running software 4.4, the last version before digital signature was
introduced. Should I upgrade? Or may be I'm missing something in 
configuration?
Thanks a lot.

Michael