[Serusers] can't find callee where Proxy and registrar are isolated.

Hi, I put the proxy and registar at the two machine. and each has its own domain name. Registrar is "suntest.com" proxy name is "sip.suntest.com". Both of which are interpreted by my DNS server. I use the mysql to store the user information. and ser.cfg uses: modparam("registrar", "use_domain", 0) when proxy deal with calling, I found that proxy don't query the callee information from the database. I sniffed the data traffic with ethereal. the Ser log said in the registrar/lookup.c lines 81 that: "lookup(): '862222' Not found in usrloc". How could I to solve that problem??? Thanks for your instructions. Best Regards. Zongjun