Here are my settings for Zimbra Desktop 1.0.3 running on Ubuntu 9.10 amd64. Replace ${HOME} with your home path.
"${HOME}/zimbra/zdesktop/linux/prism/zdclient" -webapp "${HOME}/zimbra/zdesktop/zdesktop.webapp" -override "${HOME}/zimbra/zdesktop/zdesktop.webapp/override.ini" -profile "${HOME}/zimbra/zdesktop/profile" |