JDownloader quick howto

Unfortunatly I got this error when run "nohup xvfb-run ./jd.sh &"

10 12/12/10 6:18:49 PM - INFO [jd.Main(main)] -> init Splash
Exception in thread "main" java.lang.InternalError: Can't connect to X11 window server using ':99' as the value of the DISPLAY variable.
at sun.awt.X11GraphicsEnvironment.initDisplay(Native Method)
at sun.awt.X11GraphicsEnvironment.access$100(X11GraphicsEnvironment.java:52)
at sun.awt.X11GraphicsEnvironment$1.run(X11GraphicsEnvironment.java:155)
at java.security.AccessController.doPrivileged(Native Method)
at sun.awt.X11GraphicsEnvironment.<clinit>(X11GraphicsEnvironment.java:131)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:68)
at sun.awt.X11.XToolkit.<clinit>(XToolkit.java:91)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at java.awt.Toolkit$2.run(Toolkit.java:836)
at java.security.AccessController.doPrivileged(Native Method)
at java.awt.Toolkit.getDefaultToolkit(Toolkit.java:828)
at java.awt.Toolkit.getEventQueue(Toolkit.java:1678)
at java.awt.EventQueue.isDispatchThread(EventQueue.java:807)
at javax.swing.SwingUtilities.isEventDispatchThread(SwingUtilities.java:1336)
at jd.gui.swing.GuiRunnable.start(GuiRunnable.java:103)
at jd.gui.swing.GuiRunnable.waitForEDT(GuiRunnable.java:67)
at jd.Main.main(Unknown Source)

Any idea ?

Thanks again

G