[Users] Cisco authentication

Hi all, I've a working openser and a cisco router (17xx). I'd like to authenticate the cisco router as a sip ua. If I disable www_authorize everything is working fine and the router register to the server. If I enable it and configure the router with sip-ua authentication username xxx password xxx realm xxx I see the router trying to register, but no way to make it working. I tried I think every combination of realm in www_authorize, www_challenge and so on. If I debug a successful authentication, I see a query on the db, "select ... from subscriber". If I debug the cisco auth, the server doesn't even try the query. Has somebody any hint please? TIA, -- "Work and play are words used to describe the same thing under differing conditions." Mark Twain