When you fail to registr, there are some error message output from kamailio, 
You can get those message from /var/log/message if you don`t change the default setting.
Error message can help you find the root cause and correct them.
 
 
------------------ Original ------------------
Date:  Thu, May 22, 2014 11:28 PM
To:  "sr-users"<sr-users@lists.sip-router.org>;
Subject:  [SR-Users] My kamailio.cfg has ofen not registred ,please help me check my registrar process is right or wrong
 
Hi,
My kamailio has ofen not registred ,please help me check my registrar process is right or wrong (I think the MSILO  modle maybe  tedious or  incorrect).this is my kamailio.cfg file.