Welcome to the forums,
Is this Ubuntu 6.06 LTS?
(sudo zimbra or su - zimbra)
ps auxx |grep zimbra
& then kill -9 any left over services
First check if you have another ldap instance running/installed.
You can try running (as root) ./zmfixperms from /opt/zimbra/libexec/ when you reach the step "The system will be modified - continue?"
lsof | grep TCP | grep 389
If it becomes a 99 post your hostsfile for us (/etc/hosts)
as well as:
host `hostname` <---these are backticks not quotes & don't replace hostname
dig any domain.com