i have installed Zimbra commmunity edition in a CentOS 5.4 (32bit) server.

let me know to fix this issue

The Zimbra Collaboration Suite appears already to be installed.
It can be upgraded with no effect on existing accounts,
or the current installation can be completely removed prior
to installation for a clean install.

Do you wish to upgrade? [Y]

Select the packages to install
Upgrading zimbra-core
Upgrading zimbra-ldap
Upgrading zimbra-logger
Upgrading zimbra-mta
Upgrading zimbra-snmp
Upgrading zimbra-store
Upgrading zimbra-apache
Upgrading zimbra-spell
Upgrading zimbra-memcached
Upgrading zimbra-proxy
Checking required space for zimbra-core
checking space for zimbra-store

Installing:
zimbra-core
zimbra-ldap
zimbra-logger
zimbra-mta
zimbra-snmp
zimbra-store
zimbra-apache
zimbra-spell
zimbra-memcached
zimbra-proxy

The system will be modified. Continue? [N] Y

Shutting down zimbra mail

Backing up the ldap database...done.

Removing existing packages

zimbra-ldap...done
zimbra-logger...done
zimbra-mta...done
zimbra-snmp...done
zimbra-store...done
zimbra-spell...done
zimbra-memcached...done
zimbra-proxy...done
zimbra-apache...done
zimbra-core...done

Removing deployed webapp directories
Installing packages

zimbra-core......zimbra-core-6.0.5_GA_2213.RHEL5-20100202220948.i386.rpm...done
zimbra-ldap......zimbra-ldap-6.0.5_GA_2213.RHEL5-20100202220948.i386.rpm...done
zimbra-logger......zimbra-logger-6.0.5_GA_2213.RHEL5-20100202220948.i386.rpm...done
zimbra-mta......zimbra-mta-6.0.5_GA_2213.RHEL5-20100202220948.i386.rpm...done
zimbra-snmp......zimbra-snmp-6.0.5_GA_2213.RHEL5-20100202220948.i386.rpm...done
zimbra-store......zimbra-store-6.0.5_GA_2213.RHEL5-20100202220948.i386.rpm...done
zimbra-apache......zimbra-apache-6.0.5_GA_2213.RHEL5-20100202220948.i386.rpm...done
zimbra-spell......zimbra-spell-6.0.5_GA_2213.RHEL5-20100202220948.i386.rpm...done
zimbra-memcached......zimbra-memcached-6.0.5_GA_2213.RHEL5-20100202220948.i386.rpm...done
zimbra-proxy......zimbra-proxy-6.0.5_GA_2213.RHEL5-20100202220948.i386.rpm...done

Setting defaults from saved config in /opt/zimbra/.saveconfig/config.save
HOSTNAME=localhost
LDAPHOST=
LDAPPORT=
SNMPTRAPHOST=
SMTPSOURCE=
SMTPDEST=
SNMPNOTIFY=0
SMTPNOTIFY=0
LDAPROOTPW=zimbra
LDAPZIMBRAPW=zimbra
LDAPPOSTPW=zmpostfix
LDAPREPPW=zmreplica
LDAPAMAVISPW=zmamavis
LDAPNGINXPW=zmnginx
Restoring existing configuration file from /opt/zimbra/.saveconfig/localconfig.xml...done
Operations logged to /tmp/zmsetup.02122010-220753.log
Upgrading from to 6.0.5_GA_2213
Stopping zimbra services...failed. exiting.
UPGRADE FAILED - exiting.