Since my most recent upgrade to 5.0.10, I have been unable to view other users' mail/calendars using the 'View Mail' option in the web interface. We use this feature a lot, especially when we are troubleshooting problems with Outlook calendars.

Now when I select an account or resource in the admin console and click 'View Mail', a new browser tab/window opens but it displays another copy of the admin console instead of the user/resource mail/calendar web interface.

Restarting Zimbra (zmcontrol stop; zmcontrol start) has had no effect on this behavior.

Is there a new configuration option that I have missed? I have witnessed this behavior on Firefox 3.0.3 (Ubuntu 8.04) and Internet Explorer 7 (Windows XP SP2).

The server is:
CentOS 5.2 x86_64
Zimbra 5.0.10_GA_2638.RHEL5_64.20081003025450
Zimbra webserver listens on port 8080 for normal use and 7071 for the admin console (Apache is also running on the same machine - it listens on ports 80 and 443).