FULL PRODUCT VERSION :
JRE 1.6.0_02

ADDITIONAL OS VERSION INFORMATION :
Windows XP Pro

A DESCRIPTION OF THE PROBLEM :
customer is prompted to allow our unsigned applet to run, and with additional JRE debug on, it shows sun code throwing this exception and apparently treating it as denied:

security: Invalid certificate from HTTPS server
java.lang.NullPointerException
at com.sun.deploy.ui.UIFactory.showSecurityDialog(Unknown Source)
at com.sun.deploy.security.TrustDeciderDialog.showDialog(Unknown Source)
at com.sun.deploy.security.X509ExtendedDeployTrustManager.checkServerTrusted(Unknown Source)
at com.sun.net.ssl.internal.ssl.ClientHandshaker.serverCertificate(Unknown Source)
at com.sun.net.ssl.internal.ssl.ClientHandshaker.processMessage(Unknown Source)
at com.sun.net.ssl.internal.ssl.Handshaker.processLoop(Unknown Source)
at com.sun.net.ssl.internal.ssl.Handshaker.process_record(Unknown Source)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(Unknown Source)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(Unknown Source)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(Unknown Source)
at sun.net.www.protocol.https.HttpsClient.afterConnect(Unknown Source)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(Unknown Source)
at sun.plugin.PluginURLJarFileCallBack$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.plugin.PluginURLJarFileCallBack.retrieve(Unknown Source)
at sun.net.www.protocol.jar.URLJarFile.retrieve(Unknown Source)
at sun.net.www.protocol.jar.URLJarFile.getJarFile(Unknown Source)
at sun.net.www.protocol.jar.JarFileFactory.get(Unknown Source)
at sun.net.www.protocol.jar.JarURLConnection.connect(Unknown Source)
at sun.plugin.net.protocol.jar.CachedJarURLConnection.connect(Unknown Source)
at sun.plugin.net.protocol.jar.CachedJarURLConnection.getJarFileInternal(Unknown Source)
at sun.plugin.net.protocol.jar.CachedJarURLConnection.getJarFile(Unknown Source)
at sun.misc.URLClassPath$JarLoader.getJarFile(Unknown Source)
at sun.misc.URLClassPath$JarLoader.access$600(Unknown Source)
at sun.misc.URLClassPath$JarLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.misc.URLClassPath$JarLoader.ensureOpen(Unknown Source)
at sun.misc.URLClassPath$JarLoader.<init>(Unknown Source)
at sun.misc.URLClassPath$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.misc.URLClassPath.getLoader(Unknown Source)
at sun.misc.URLClassPath.getLoader(Unknown Source)
at sun.misc.URLClassPath.getResource(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at sun.applet.AppletClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.applet.AppletClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.applet.AppletClassLoader.loadCode(Unknown Source)
at sun.applet.AppletPanel.createApplet(Unknown Source)
at sun.plugin.AppletViewer.createApplet(Unknown Source)
at sun.applet.AppletPanel.runLoader(Unknown Source)
at sun.applet.AppletPanel.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
security: Adding certificate in Deployment denied certificate store
security: Added certificate in Deployment denied certificate store


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
I could't reproduce it myself, our one customer gets this repeatedly.

Try to run the unsigned applet, get prompted whether to trust the content to run, click Yes to accept it

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
on my machine I see this:

security: Invalid certificate from HTTPS server
security: Adding certificate in Deployment session certificate store
security: Added certificate in Deployment session certificate store
security: Saving certificates in Deployment session certificate store
security: Saved certificates in Deployment session certificate store

ACTUAL -
see problem description, applet does not run becuase it is treated as denied

ERROR MESSAGES/STACK TRACES THAT OCCUR :
no error message, but NullPointerException in java console with debug on

REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
us MS jvm