Problem with data synchronization between zabbix_server and zabbix_proxy.

This problem has been found when using autodiscovery:
Has been created autodiscovery rule on the zabbix server, then it has been deleted and then has been created new autodiscovery rule, but on the zabbix proxy server this new discovery rule does not appeared.

In the zabbix_proxy.log appears error:

20100120:042441 [Z3005] Query failed: [1062] Duplicate entry 'memTotalSwap' for key 'items_1' [insert into items (itemid,type,snmp_community,snmp_oid,snmp_port,hostid,key_,delay,status,value_type,trapper_hosts,units,multiplier,delta,snmpv3_securityname,snmpv3_securitylevel,snmpv3_authpassphrase,snmpv3_privpassphrase,formula,logtimefmt,templateid,valuemapid,delay_flex,params,ipmi_sensor) values (173105,1,'host1','.1.3.6.1.4.1.2021.4.3.0',161,18975,'memTotalSwap',900,0,3,'','B',1,0,'',0,'','','1024','',22252,0,'','DSN=<database source name>
nuser=<user name>\\npassword=<password>
nsql=<query>','');

As a result on the zabbix_server and on the zabbix_proxy in the DB "drules" tables appears different discovery rules with different druleid's, so on the zabbix_proxy is active old discovery rule.