Can't start the slapd instance configured as a sync replication engine.

[zhp <zhp@ustc.edu>]

I run my slapd deamon and the sync replication on the same host.
They were bind on different port, and they used different configuration 
file and different db directory.
I configured the slapd as a sync replication engine in the configuration 
file like this:
syncrepl rid=1
 provider=ldap://127.0.0.1:389
 type=refreshAndPersist
 interval=00:00:01:00
 searchbase="dc=example,dc=com"
 filter="(objectClass=*)"
 scope=sub
 attrs="cn,description"
 retry=1,2,3,4,5,+
 schemachecking=off
 updatedn="cn=replica,dc=example,dc=com"
 bindmethod=simple
 binddn="cn=Manager,dc=example,dc=com"
 credentials=secret
updateref ldap://127.0.0.1
---------------------------------------
I can't start my sync replication engine after i started the slapd 
deamon which worked as a provider. But if i started my replicaton engine 
first and then the slapd deamon, it worked well.

I started the sync replication replication like this:
#slapd -h "ldap://0.0.0.0:666"; -n syncrepl -f 
/usr/local/openldap2.2/etc/openldap/syncrepl.conf.
   What is the matter? Thanks very much.
p.zhang