I have been using zdesktop for a couple of months. On Jan 26th I upgraded to 2.01 B10659.
It has bee working without issue until this morning.
Most time when I attempt starting it, I get the usual light coloured box on the desktop. After a minute or 2, it goes away. Zip. No error messages. Nothing. Just gone. Top does show it as still running and things continue to be put in the log files (I notice nothing that looks like an error though).
I re-installed the entire package once, and the user portion a couple of times.
Once, after re-installing the "user" client "user-install.pl", it went on longer than usual with the spinning wheel. I then got a message box about a script stopped running on the page. After OKing that, I got another message box about being unable to connect to desktop 0:0.
I have not installed anything new since a couple of days ago. It worked fine for at least 2 days after installing any new software on the box. Fedora di however have a couple of updates late yesterday. They seemed to be the usual sorts of updates and I just let it do it.
It was on the next boot that Zimbra Desktop now longer worked. It was running when the updates were being installed and I noticed nothing unusual at that time.