Not sure it's a bona fide bug
There is a bug report filed against Ubuntu. I think it should just be 'noted' for Ubuntu 8.04 server users. It's not Zimbra's problem, though ti does cause problems for Zimbra :)
I'm testing my migration right now - after the above changes.
https/SSL webclient problem on 8.04
We had some problems with SSL on the web client. Certificate (commercial) worked fine on the admin console but not in the web client login screen. Got standard Firefox errors about unable to connect. Seems also that with 5.0.11 on Hardy the log file locations are different to the old days, so could not find the Tomcat logs!
Anyhow seems that the standard install didnt configure to allow SSL but thanks to your Hardy wiki entry, minds were cast back to requiring the
and that seemed to work fine. Just seemed odd mixed wasnt at least configured as a default during the install.