i have install zimbra versio zcs-5.0.9_GA_2533.RHEL5 in centos 5.2, when i try to start zimbra, i got this error msg

[zimbra@email ~]$ zmcontrol start
Host localhost
Starting ldap...Done.
FAILED
Failed to start slapd. Attempting debug start to determine error.

[zimbra@email ~]$ ldap start
Failed to start slapd. Attempting debug start to determine error.

any body know how to fix this error