Rooms and Resources Revervations db and "Applet dominoActionBar notinited", followed by "Loading Java Applet Failed..."

We are using the Rooms and Resource Reservations db. When users try to access it via the web gray boxes appear with status bar saying “Applet dominoActionBar notinited”, followed by “Loading Java Applet Failed…”

We are using Windows XP Service Pack2.

What’s the cause of this?

Subject: Not sure, but

The Button bar is a java applet that takes a few seconds to load - is the jvm on the local workstation up to date? I’m guessing that some users can open it ok.