I am having strange kind of problem with zcs 6 and had it with 5.18 as well. If I create a new appointment and add note to it I can read the note no problem within zimbra account either web or desktop client.
If I publish calendar via sharing/public and accessing same calendar as a web-page it doesn't show me any notes inside of the appointment (if I click on it to read details). I was able to work around this by typing notes in ms word and then copy/past it into the appointment notes, but in version 6 it doesn't seems to work anymore. So I am not sure why would it work if I past text from the word and would not if I type into note window directly. Does anybody know how to fix that? Very annoying.