Java Security

Hello,
I developed a swing application using JFileChooser. I'll recommend using the security manager and deliver a simple policy. The application works properly. But it throws an exception in XP:

Exception in thread "Basic L&F File Loading Thread" java.security.AccessControlE

xception: access denied (java.lang.RuntimePermission modifyThread)

at java.security.AccessControlContext.checkPermission(Unknown Source)

at java.security.AccessController.checkPermission(Unknown Source)

at java.lang.SecurityManager.checkPermission(Unknown Source)

at java.lang.SecurityManager.checkAccess(Unknown Source)

at java.lang.Thread.checkAccess(Unknown Source)

at java.lang.Thread.interrupt(Unknown Source)

at java.util.concurrent.FutureTask$Sync.innerCancel(Unknown Source)

at java.util.concurrent.FutureTask.cancel(Unknown Source)

at sun.awt.shell.Win32ShellFolderManager2$ComInvoker.invoke(Unknown Sour

ce)

at javax.swing.plaf.basic.BasicDirectoryModel$LoadFilesThread.run0(Unkno

wn Source)

at javax.swing.plaf.basic.BasicDirectoryModel$LoadFilesThread.run(Unknow

n Source)

It seems as if the JFileChooser does not really need this permission. So I will recommend to ignore it. Hackers would probably take it as an invitation.
Is this a bug?
In a small test project I can see that setting a file filter causes this problem.
I need a explanation for the users. Why does JFileChooser expect this permission?