An exception comes to occur in jdk5.0u17(and later versions), but does not in jdk5.0u16.

C:\users\licensees\NPE-null-FileChooser>appletviewer -J-Djava.security.policy=policy a.html
Exception in thread "Basic L&F File Loading Thread" java.security.AccessControlException: access denied (java.io.FilePermission C:\Documents and Settings\tbaba\My Documents read)
        at java.security.AccessControlContext.checkPermission(AccessControlContext.java:264)
        at java.security.AccessController.checkPermission(AccessController.java:427)
        at java.lang.SecurityManager.checkPermission(SecurityManager.java:532)
        at java.lang.SecurityManager.checkRead(SecurityManager.java:871)
        at sun.awt.shell.Win32ShellFolder2.listFiles(Win32ShellFolder2.java:523)

        at javax.swing.filechooser.FileSystemView.getFiles(FileSystemView.java:422)
        at javax.swing.plaf.basic.BasicDirectoryModel$LoadFilesThread.run(BasicDirectoryModel.java:211)


REPRODUCE:
1) Compile the attached a.java
2) Set the attached "policy"and a.html filse to the dir. of 1)
3) Invoke the following command line.
 appletviewer -J-Djava.security.policy=policy a.html

You will see the above exception.
(for a littl bit more details, please see the attached exceptions-in-jdk50ux)