重建 oracle 10G 的em出错 帮忙看一下

[oracle@fd ~]$ emca -config dbcontrol db -repos create
STARTED EMCA at Oct 21, 2010 12:20:45 PM
EM Configuration Assistant, Version 10.2.0.5.0 Production
Copyright (c) 2003, 2009, Oracle.  All rights reserved.
Enter the following information:
Database SID: orcl
Listener port number: 1522
Password for SYS user:  
Password for DBSNMP user:  
Password for SYSMAN user:  
Email address for notifications (optional):
Outgoing Mail (SMTP) server for notifications (optional):
-----------------------------------------------------------------
You have specified the following settings
Database ORACLE_HOME ................ /u01/app/oracle/10g
Local hostname ................ fd.ssk.com
Listener port number ................ 1522
Database SID ................ orcl
Email address for notifications ...............
Outgoing Mail (SMTP) server for notifications ...............
-----------------------------------------------------------------
Do you wish to continue? [yes(Y)/no(N)]: Y
Oct 21, 2010 12:21:10 PM oracle.sysman.emcp.EMConfig perform
INFO: This operation is being logged at /u01/app/oracle/10g/cfgtoollogs/emca/orcl/emca_2010-10-21_12-20-45-PM.log.
Oct 21, 2010 12:21:12 PM oracle.sysman.emcp.EMReposConfig createRepository
INFO: Creating the EM repository (this may take a while) ...
Oct 21, 2010 12:21:19 PM oracle.sysman.emcp.EMReposConfig createRepository
WARNING: ORA-00955: name is already used by an existing object
Oct 21, 2010 12:21:19 PM oracle.sysman.emcp.EMReposConfig invoke
SEVERE: Error creating the repository
Oct 21, 2010 12:21:19 PM oracle.sysman.emcp.EMReposConfig invoke
INFO: Refer to the log file at /u01/app/oracle/10g/cfgtoollogs/emca/orcl/emca_repos_create_<date>.log for more details.
Oct 21, 2010 12:21:19 PM oracle.sysman.emcp.EMConfig perform
SEVERE: Error creating the repository
Refer to the log file at /u01/app/oracle/10g/cfgtoollogs/emca/orcl/emca_2010-10-21_12-20-45-PM.log for more details.
Could not complete the configuration. Refer to the log file at /u01/app/oracle/10g/cfgtoollogs/emca/orcl/emca_2010-10-21_12-20-45-PM.log for more details.
[oracle@fd ~]$
上面的是建立的是时候出错说出错在日志里
[oracle@fd j2ee]$ tail /u01/app/oracle/10g/cfgtoollogs/emca/orcl/emca_repos_create_2010-10-21_12-21-12-PM.log
No errors.
No errors.
No errors.
Creating Tables
Creating Tables
CREATE PUBLIC SYNONYM MGMT_TARGET_BLACKOUTS FOR MGMT_BLACKOUT_STATE
                      *
ERROR at line 1:
ORA-00955: name is already used by an existing object
[oracle@fd j2ee]$
[oracle@fd j2ee]$ tail /u01/app/oracle/10g/cfgtoollogs/emca/orcl/emca_2010-10-21_12-20-45-PM.log
Oct 21, 2010 12:21:19 PM oracle.sysman.emcp.EMConfig perform
CONFIG: Stack Trace:
oracle.sysman.emcp.exception.EMConfigException: Error creating the repository
        at oracle.sysman.emcp.EMReposConfig.invoke(EMReposConfig.java:226)
        at oracle.sysman.emcp.EMReposConfig.invoke(EMReposConfig.java:141)
        at oracle.sysman.emcp.EMConfig.perform(EMConfig.java:171)
        at oracle.sysman.emcp.EMConfigAssistant.invokeEMCA(EMConfigAssistant.java:494)
        at oracle.sysman.emcp.EMConfigAssistant.performConfiguration(EMConfigAssistant.java:1161)
        at oracle.sysman.emcp.EMConfigAssistant.statusMain(EMConfigAssistant.java:478)
        at oracle.sysman.emcp.EMConfigAssistant.main(EMConfigAssistant.java:426)
[oracle@fd j2ee]$
就是这样的错误信息 ，我已经重建了很多次了，一直还是这样的，我是新手，大家给点建议，

先删除  em  repository
emca -deconfig dbcontrol db -repos drop
然后重建之

1. 默认OEM 连接：http://主机名:1158/em
2. 假设连接失败需要做以下配置：
重新配置dbconsole的步骤
emca -repos drop
emca -repos create
emca -config dbcontrol db
emctl start dbconsole
假设过程中报错：ORA-20001: SYSMAN already exists..
需先执行：
SQL> drop user sysman cascade;
SQL> drop role MGMT_USER;
SQL> drop user MGMT_VIEW cascade;
SQL> drop public synonym MGMT_TARGET_BLACKOUTS;
SQL> drop public synonym SETEMVIEWUSERCONTEXT;
再执行：重新配置dbconsole的步骤
假设连接进入OEM界面后，显示无法连接数据库实例。
需要修改hosts文件。

恩  这位兄弟比较详细

问题解决  谢谢

互相学习啊。