The fix for 6730439 introduced the Enhanced Security Warning on the X11 platforms. Before that fix unsigned application were not allowed to use non-opaque windows (as introduced in 6u10). With the fix for 6730439 the effect was enabled for such applications on X11. However, due to a typo this now causes a StackOverflowException to be thrown whenever an applications enables the effect. The stack trace is as follows:

        at sun.awt.X11.XWindowPeer.setOpaque(XWindowPeer.java:1936)
        at java.awt.Window.applyOpaque(Window.java:3367)
        at java.awt.Window.access$800(Window.java:132)
        at java.awt.Window$1.setOpaque(Window.java:3426)
        at sun.awt.X11.XWindowPeer.setOpaque(XWindowPeer.java:1936)
        at java.awt.Window.applyOpaque(Window.java:3367)
        at java.awt.Window.access$800(Window.java:132)
        at java.awt.Window$1.setOpaque(Window.java:3426)