[Error JRViewer in jre 1.7]

Hi,

I have a report displayed in JRViewer with JasperReports 4.0.1 that run in Firefox 3.6 but when i tried viewing the report in the applet, i am getting a class cast
exception at runtime:

Java Plug-in 1.6.0_27
Usar versión JRE 1.7.0_03-b05 Java HotSpot Client VM

java.lang.ExceptionInInitializerError
 at com.sun.deploy.net.protocol.https.Handler.openConnection(Unknown Source)
 at java.net.URL.openConnection(Unknown Source)
 at sun.net.www.protocol.jar.JarURLConnection.<init>(Unknown Source)
 at sun.plugin.net.protocol.jar.CachedJarURLConnection.<init>(Unknown Source)
 at sun.plugin.net.protocol.jar.Handler.openConnection(Unknown Source)
 at java.net.URL.openConnection(Unknown Source)
 at com.sun.deploy.security.DeployURLClassPath$JarLoader.getJarFile(Unknown Source)
 at com.sun.deploy.security.DeployURLClassPath$JarLoader.access$800(Unknown Source)
 at com.sun.deploy.security.DeployURLClassPath$JarLoader$1.run(Unknown Source)
 at java.security.AccessController.doPrivileged(Native Method)
 at com.sun.deploy.security.DeployURLClassPath$JarLoader.ensureOpen(Unknown Source)
 at com.sun.deploy.security.DeployURLClassPath$JarLoader.<init>(Unknown Source)
 at com.sun.deploy.security.DeployURLClassPath$3.run(Unknown Source)
 at java.security.AccessController.doPrivileged(Native Method)
 at com.sun.deploy.security.DeployURLClassPath.getLoader(Unknown Source)
 at com.sun.deploy.security.DeployURLClassPath.getLoader(Unknown Source)
 at com.sun.deploy.security.DeployURLClassPath.getResource(Unknown Source)
 at sun.plugin2.applet.Plugin2ClassLoader$2.run(Unknown Source)
 at java.security.AccessController.doPrivileged(Native Method)
 at sun.plugin2.applet.Plugin2ClassLoader.findClassHelper(Unknown Source)
 at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source)
 at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
 at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
 at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
 at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
 at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
 at java.lang.ClassLoader.loadClass(Unknown Source)
 at sun.plugin2.applet.Plugin2ClassLoader.loadCode(Unknown Source)
 at sun.plugin2.applet.Plugin2Manager.createApplet(Unknown Source)
 at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
 at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassCastException: sun.security.ssl.X509TrustManagerImpl cannot be cast to com.sun.net.ssl.internal.ssl.X509ExtendedTrustManager
 at com.sun.deploy.security.X509ExtendedDeployTrustManager.<init>(Unknown Source)
 at com.sun.deploy.net.protocol.https.Handler$Initializer$1.run(Unknown Source)
 at java.security.AccessController.doPrivileged(Native Method)
 at com.sun.deploy.net.protocol.https.Handler$Initializer.<clinit>(Unknown Source)
 ... 31 more
Exception: java.lang.ExceptionInInitializerError

Do I need to change something? Please help.

Thanks, Jesús