I performed an upgrade of FOSS Zimbra 6.0.4 Ga to 6.0.5 GA tonight and had one error:
Notifying Zimbra of installation via http://www.zimbra.com/cgi-bin/notify...email@example.com
ERROR: Notification failed
I tried accessing the URL manually from my laptop and the webserver could not find the requested URL.
As this appears to be a Zimbra problem not my installation problem I won't provide further details unless they are needed to help identify the problem.
install file is: zcs-6.0.5_GA_2213.UBUNTU8.20100202225756.tgz