FULL PRODUCT VERSION :
java version "1.7.0_06"
Java(TM) SE Runtime Environment (build 1.7.0_06-b24)
Java HotSpot(TM) Client VM (build 23.2-b09, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]

EXTRA RELEVANT SYSTEM CONFIGURATION :
JRE 1.7.0_5 was updated to JRE 1.7.0_6

A DESCRIPTION OF THE PROBLEM :
We are using applets.
After updating from JRE 1.7.0_5 to JRE 1.7.0_6 some applets could not start any more.
In the stacktrace we see only jdk classes, none of our classes:
java.lang.IllegalStateException: zip file closed
at java.util.zip.ZipFile.ensureOpen(Unknown Source)
at java.util.zip.ZipFile.entries(Unknown Source)
at java.util.jar.JarFile.entries(Unknown Source)
at java.util.jar.JarVerifier.unsignedEntryNames(Unknown Source)
at java.util.jar.JarVerifier.getCodeSources(Unknown Source)
at java.util.jar.JarFile.getCodeSources(Unknown Source)
at java.util.jar.JavaUtilJarAccessImpl.getCodeSources(Unknown Source)
at com.sun.deploy.cache.DeployCacheJarAccessImpl.getCodeSources(Unknown Source)
at com.sun.deploy.security.CPCallbackHandler$ParentCallback.openClassPathElement(Unknown Source)
at com.sun.deploy.security.DeployURLClassPath$JarLoader.getJarFile(Unknown Source)
at com.sun.deploy.security.DeployURLClassPath$JarLoader.access$1000(Unknown Source)
at com.sun.deploy.security.DeployURLClassPath$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$2.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.plugin2.applet.Plugin2ClassLoader.findClassHelper(Unknown Source)
at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadCode(Unknown Source)
at sun.plugin2.applet.Plugin2Manager.initAppletAdapter(Unknown Source)
at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)



REGRESSION. Last worked in version 7

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Some of our applets are working as before, some are throwing these exceptions. Always the same applets throw exceptions.
The applets are working in case of calling the web page from a browser with an JRE 1.6.0_34 plugin or with a plugin <= 1.7.0_5


REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
Don't use JRE 1.7.0_6 plugin.