Scenario I:
Load the following applet inside the browser and try to refresh the browser
http://sqeweb.sfbay.sun.com/deployment2/jitu/deployment_JDK7_int_ws/deployment/src/plugin/manual/html/ThreadLeak.html
If following exceptions are getting raised then bug is reproduced:
java.lang.InterruptedException
    at java.lang.Object.wait(Native Method)
    at sun.plugin2.message.Queue.waitForMessage(Queue.java:86)
    at sun.plugin2.message.Pipe.receive(Pipe.java:103)
    at sun.plugin2.main.client.MessagePassingExecutionContext.getProxyList(MessagePassingExecutionContext.java:130)
    at sun.plugin2.main.client.PluginProxySelector.select(PluginProxySelector.java:66)
    at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:742)
    at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:672)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:997)
    at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:391)
    at sun.plugin2.applet.Applet2ClassLoader.getBytes(Applet2ClassLoader.java:348)
    at sun.plugin2.applet.Applet2ClassLoader.access$100(Applet2ClassLoader.java:47)
    at sun.plugin2.applet.Applet2ClassLoader$1.run(Applet2ClassLoader.java:151)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.plugin2.applet.Applet2ClassLoader.findClass(Applet2ClassLoader.java:148)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:324)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:269)
    at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:337)
    at sqe.ThreadLeakTest.destroy(ThreadLeakTest.java:93)
    at sun.plugin2.applet.Applet2Manager$AppletExecutionRunnable.run(Applet2Manager.java:834)
    at java.lang.Thread.run(Thread.java:644)
java.lang.RuntimeException: java.lang.NullPointerException
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:962)
    at sun.net.www.protocol.http.HttpURLConnection.getHeaderField(HttpURLConnection.java:2110)
    at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:400)
    at sun.plugin2.applet.Applet2ClassLoader.getBytes(Applet2ClassLoader.java:348)
    at sun.plugin2.applet.Applet2ClassLoader.access$100(Applet2ClassLoader.java:47)
    at sun.plugin2.applet.Applet2ClassLoader$1.run(Applet2ClassLoader.java:151)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.plugin2.applet.Applet2ClassLoader.findClass(Applet2ClassLoader.java:148)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:324)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:269)
    at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:337)
    at sqe.ThreadLeakTest.destroy(ThreadLeakTest.java:93)
    at sun.plugin2.applet.Applet2Manager$AppletExecutionRunnable.run(Applet2Manager.java:834)
    at java.lang.Thread.run(Thread.java:644)
Caused by: java.lang.NullPointerException
    at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:742)
    at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:672)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:997)
    at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:391)
    ... 11 more
java.lang.reflect.InvocationTargetException
    at com.sun.deploy.util.DeployAWTUtil.invokeAndWait(DeployAWTUtil.java:116)
    at sun.plugin2.applet.Applet2Manager.runOnEDT(Applet2Manager.java:2308)
    at sun.plugin2.applet.Applet2Manager.access$2500(Applet2Manager.java:82)
    at sun.plugin2.applet.Applet2Manager$AppletExecutionRunnable.run(Applet2Manager.java:838)
    at java.lang.Thread.run(Thread.java:644)
Caused by: java.lang.NullPointerException
    at sun.plugin2.applet.Applet2Manager$AppletExecutionRunnable$4.run(Applet2Manager.java:840)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:217)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:610)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:276)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:201)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:191)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:186)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:178)


Scenario II:
Load the following applet inside the browser
http://sqeweb.sfbay.sun.com/deployment2/jitu/deployment_JDK7_int_ws/deployment/src/plugin/manual/html/InfiniteLoopTest.html

Following exception is getting thrown on page switching or on refreshing the browser
java.lang.NullPointerException
    at sun.awt.SunToolkit.postEvent(SunToolkit.java:615)
    at com.sun.deploy.util.DeployAWTUtil.invokeAndWait(DeployAWTUtil.java:110)
    at sun.plugin2.applet.Applet2Manager.runOnEDT(Applet2Manager.java:2308)
    at sun.plugin2.applet.Applet2Manager.setupGrayBoxPainter(Applet2Manager.java:1185)
    at sun.plugin2.applet.Applet2Manager.access$900(Applet2Manager.java:82)
    at sun.plugin2.applet.Applet2Manager$AppletExecutionRunnable.run(Applet2Manager.java:692)
    at java.lang.Thread.run(Thread.java:644)
exception
Exception in thread "thread applet-InfiniteLoopTest.class-3" java.lang.NullPointerException
    at sun.awt.SunToolkit.postEvent(SunToolkit.java:615)
    at com.sun.deploy.util.DeployAWTUtil.invokeAndWait(DeployAWTUtil.java:110)
    at sun.plugin2.applet.Applet2Manager.runOnEDT(Applet2Manager.java:2308)
    at sun.plugin2.applet.Applet2Manager.access$2500(Applet2Manager.java:82)
    at sun.plugin2.applet.Applet2Manager$AppletExecutionRunnable.run(Applet2Manager.java:866)
    at java.lang.Thread.run(Thread.java:644)