How to set up a Cisco 8851 [SIP]?

Question

SIP

Greetings!
The third day we are trying to configure the Cisco 8851 to work with Mango Office, it does not work. The firmware is like the latest, sip88xx.11-5-1SR1-1. The bottom line is this - when one line is configured, everything seems to work. But when there are two lines, dancing with a tambourine begins. Usecallmanager.nz was used for settings. The phone stupidly does not register with two lines, or it registers, but the registration flies. We tried with our asterisk - the same thing. The logs say something like this:
Asterisk Ready.
[Nov 22 21:13:49] WARNING[4205]: chan_sip.c:17091 check_auth: username mismatch, have "user1", digest has "user2"
Here is a link to SEPMAC.cnf.xml .
What to do?