I've been using Zimbra Desktop 1.04 for a while now, and decided to upgrade to the last version. Bad move!
- Message content doesn't show up unless you double-click on the message header (and hence open a new window)
- Behaviour is much slower than before (~ 2 times more, when it doesn't just hang)
- Uses much more ram for virtualy no real improvement (as far as I can see).

Can you provide a link to an older version, even if the price is to re-sync the whole mail folder?