None of the applets in Ultrastudio.org is capable to run on Lobo. When Lobo identifies itself as Internet Explorer (default), it receives OBJECT tags from this server, otherwise it receives APPLET tags. Applet in both cases is packages in the .jar file, and Lobo itself is running of the java virtual machine that is recent enough to support the applets.
Ultrastudio.org applets run flawlessly in Firefox, Internet Explorer, Safari, Flock and even the old Netscape Navigator, and the "applet" version is really just an old plain "applet" tag from the textbook. This may indicate a rather general bug that it is better to fix.