Sometimes Java applications running on a host do not show on the viewer during an RC session. The java application window shows a black or white square rather than the actual screen contents. This is known to show with nVidia graphic cards more often than on other brands, even though the latest video drivers have been installed.
The side effects are minimal:
"Load driver on start" may cause the startup of the host to be a little bit delayed as the driver is started at the boot of the workstation rather than at the beginning of a session. There are some rare occurrences where this setting prevented some applications, such as DVD players, from working.
"Video capture mode" set to polling may have a slightly worse performance than the default Driver capture mode.
You might want to try if either of the 2 settings is enough to have the java app displayed well, if you encounter one of the side effects described.