Depends on the version of the applet you are using - we replaced the Flash-based one with a DHTML one when we released version 5.1 (Dec 08).
If you're using the flash-based applet, reloading the page (or loading a different page) may fix it because the applet uses a persistent connection while it is loaded. Check your event logs for connection errors, and check the System -> Security tab for applet security settings (ports, authentication).
I've not seen this problem with the newer DHTML version - this just makes direct requests from your browser to the admin server. Wireshark or livehttpheaders may help here.
You can restart the Zeus software, but that's a very drastic measure. If the problem persists, send a problem description and a tech support report to our support team (
support@zeus.com, put customer number in subject line).
regards
Owen