[Serusers] Some problem about auth module

Dear ser users, I encountered a strange problem today. I use ser 0.8.14 downloaded from berlios.de. My system is RedHad linux9. Originally, my ser works good for me with auth module loaded. I have the following line in my ser.cfg. if( !www_challenge("xxx.xxx.xx", "subscriber") ) { www_authorize( "xxx.xxx.xx", "1" ); break; }; With this, even my grand stream can login into my server. And some other SJphone clients work really good for me. Although the domain name "xxx.xxx.xx" does not exist. When I use a real domain name called "xxx.xxx" I change ser.cfg like this if( !www_challenge( "xxx.xxx","subscriber" ) ) { www_authorize( "xxx.xxx", "1" ); break; }; My grandstream can't even login. And all my SJphone clients can't work well too. Any hints about such problem? Thanks in advance. Sincerely, Kun