Under some scenarios multiple applets on same page fails to load by throwing different exceptions listed below. Issues are only noticed by JNLP based applets, same scenarios works fine with tarditional applets
Test page:
http://sqeweb.sfbay.sun.com/deployment2/jitu/plug-bug/ojiliveconnect/src/MultiTestAppletJNLP.html

Exceptions thrown:
1)java.io.FileNotFoundException: C:\Documents and Settings\jitu\Application Data\Sun\Java\Deployment\cache\6.0\56\5c628778-1d3fee3d.idx (The process cannot access the file because it is being used by another process)
at java.io.RandomAccessFile.open(Native Method)
at java.io.RandomAccessFile.<init>(Unknown Source)
at com.sun.deploy.util.SyncFileAccess.openLockFileObject(Unknown Source)
at com.sun.deploy.util.SyncFileAccess.openLockRandomAccessFile(Unknown Source)
at com.sun.deploy.cache.CacheEntry.openLockIndexFile(Unknown Source)
at com.sun.deploy.cache.CacheEntry.access$000(Unknown Source)
at com.sun.deploy.cache.CacheEntry$8.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
network: ResponseCode for http://sqeweb.sfbay.sun.com/deployment2/jitu/plug-bug/ojiliveconnect/src/MultipleAppTest.jar : 200
network: Encoding for http://sqeweb.sfbay.sun.com/deployment2/jitu/plug-bug/ojiliveconnect/src/MultipleAppTest.jar : null
network: Sever response: (length: 1361, lastModified: Tue Nov 02 10:19:53 PDT 2010, downloadVersion: null, mimeType: application/java-archive)
at com.sun.deploy.cache.CacheEntry.updateIndexHeaderOnDisk(Unknown Source)
at com.sun.deploy.cache.Cache.processNewCacheEntry(Unknown Source)
at com.sun.deploy.cache.Cache.downloadResourceToCache(Unknown Source)
at com.sun.deploy.net.DownloadEngine.actionDownload(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getCacheEntry(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getCacheEntry(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getResourceCacheEntry(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getResourceCacheEntry(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getResource(Unknown Source)
at com.sun.javaws.LaunchDownload$DownloadTask.call(Unknown Source)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
basic: exception: Unable to load resource: http://sqeweb.sfbay.sun.com/deployment2/jitu/plug-bug/ojiliveconnect/src/MultipleAppTest.jar.
exception: Unable to load resource: http://sqeweb.sfbay.sun.com/deployment2/jitu/plug-bug/ojiliveconnect/src/MultipleAppTest.jar.
com.sun.deploy.net.FailedDownloadException: Unable to load resource: http://sqeweb.sfbay.sun.com/deployment2/jitu/plug-bug/ojiliveconnect/src/MultipleAppTest.jar
at com.sun.deploy.net.DownloadEngine.actionDownload(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getCacheEntry(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getCacheEntry(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getResourceCacheEntry(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getResourceCacheEntry(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getResource(Unknown Source)
at com.sun.javaws.LaunchDownload$DownloadTask.call(Unknown Source)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by:
java.io.FileNotFoundException: index file not found
at com.sun.deploy.util.SyncFileAccess.openLockFileObject(Unknown Source)
at com.sun.deploy.util.SyncFileAccess.openLockRandomAccessFile(Unknown Source)
at com.sun.deploy.cache.CacheEntry.openLockIndexFile(Unknown Source)
at com.sun.deploy.cache.CacheEntry.access$000(Unknown Source)
at com.sun.deploy.cache.CacheEntry$8.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.deploy.cache.CacheEntry.updateIndexHeaderOnDisk(Unknown Source)
at com.sun.deploy.cache.Cache.processNewCacheEntry(Unknown Source)
at com.sun.deploy.cache.Cache.downloadResourceToCache(Unknown Source)
at com.sun.deploy.net.DownloadEngine.actionDownload(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getCacheEntry(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getCacheEntry(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getResourceCacheEntry(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getResourceCacheEntry(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getResource(Unknown Source)
at com.sun.javaws.LaunchDownload$DownloadTask.call(Unknown Source)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

2) java.lang.NullPointerException
at sun.plugin2.applet.Plugin2ClassLoader.getTrustedCodeSources(Unknown Source)
at com.sun.deploy.security.CPCallbackHandler$ParentCallback.strategy(Unknown Source)
at com.sun.deploy.security.CPCallbackHandler$ParentCallback.openClassPathElement(Unknown Source)
at com.sun.deploy.security.DeployURLClassPath$JarLoader.getJarFile(Unknown Source)
at com.sun.deploy.security.DeployURLClassPath$JarLoader.access$800(Unknown Source)
at com.sun.deploy.security.DeployURLClassPath$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$2.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.plugin2.applet.Plugin2ClassLoader.findClassHelper(Unknown Source)
at sun.plugin2.applet.JNLP2ClassLoader.findClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadCode(Unknown Source)
at sun.plugin2.applet.Plugin2Manager.createApplet(Unknown Source)
at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

3) Below mentioned exception is rarerly thrown
java.lang.RuntimeException: ERROR: Failed to recover corrupt cache entry
at com.sun.deploy.cache.CacheEntry.recover(Unknown Source)
at com.sun.deploy.cache.CacheEntry.getCodeSourceCache(Unknown Source)
at com.sun.deploy.cache.CacheEntry.getCodeSources(Unknown Source)
at com.sun.deploy.cache.CachedJarFile.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$800(Unknown Source)
at com.sun.deploy.security.DeployURLClassPath$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.JNLP2ClassLoader.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(Unknow