The update may have toggled an important setting in your Java Preferences. Check to see if the "Enable applet plug-in and Web Start appications" checkbox in the Java Preferences has been unchecked. If so, checking it is likely to solve the problem you reported.
Nope -- that's not it. The "enable" box is checked (there was a prompt to enable this when I first went to load the FMS Admin applet...)
I rebooted the server machine over the weekend and everything was fine after that. It may have just been a coincidence.
Glad to hear the problem got resolved, even if it was a 'mystery fix.'