LDAP stopped working after yum upgrade to CentOS 5.4

[powrrrplay]

We did a YUM upgrade this past Saturday night. The upgrade took us from Centos 5.3 to 5.4, 64 bit. Although Zimbra seems to run ok, mind you at times very slow, a zmcontrol status shows:


[zimbra@mail ]$ zmcontrol status
Unable to determine enabled services from ldap.
Enabled services read from cache. Service list may be inaccurate.
Host mail.xxx.com
antispam Running
antivirus Running
ldap Running
logger Running
mailbox Running
mta Running
snmp Running
spell Running
stats Running
[zimbra@mail ]$

I can't find anything in the logs out of the ordinary except for this:
zimbramon[7844]: 7844:info: zmmtaconfig: Sleeping...Key lookup failed.


We have restarted the server a few times but this does not fix the LDAP problem. It seem like the centos upgrade has affected zimbra LDAP. Can I reinstall 64 bit zimbra 6.04 to try and fix LDAP?