User preferences in your home account for an earlier version of the GNOME Desktop might be partly incompatible with the version on the Java DS Release 3.
Workaround: Reset your preferences. Perform the following steps:
Log out of the Java Desktop System.
Click Session and choose Failsafe terminal.
In the failsafe terminal window, enter the following commands:
% gnome-cleanup exit
Log in again.
Your GNOME preferences are now reset.