Steps to reproduce this issue

1) drag the applet and close the browser (ie7 or FF3).
2) It will create a shortcut on the desktop and click the shortcut.

it throws the following exception
ava.lang.NoClassDefFoundError: netscape/javascript/JSException
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Unknown Source)
at java.lang.Class.getConstructor0(Unknown Source)
at java.lang.Class.newInstance0(Unknown Source)
at java.lang.Class.newInstance(Unknown Source)
at com.sun.javaws.Launcher.executeApplet(Unknown Source)
at com.sun.javaws.Launcher.executeMainClass(Unknown Source)
at com.sun.javaws.Launcher.doLaunchApp(Unknown Source)
at com.sun.javaws.Launcher.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: netscape.javascript.JSException
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at com.sun.jnlp.JNLPClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
... 10 more

Java Console shows the following error
#### Java Web Start Error:
#### java.lang.NoClassDefFoundError: netscape/javascript/JSException
Exception in thread "Thread-30" java.lang.NullPointerException
at com.sun.javaws.ui.DownloadWindowHelper$2.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

I have pointed my javafx.runtime.properties to:
runtime.url=http://jfx.sfbay.sun.com/hudson/job/franca-integration/438/label=windows-i586/artifact/build/windows-i586/release/javaws/