J2SE Version (please include all output from java -version flag):
  java version "1.6.0-rc"
  Java(TM) 2 Runtime Environment, Standard Edition (build 1.6.0-rc-b60)
  Java HotSpot(TM) Client VM (build 1.6.0-rc-b60, mixed mode, sharing)

Does this problem occur on J2SE 1.4.x or 5.0.x ?  Yes / No (pick one)
  No

Operating System Configuration Information (be specific):
  Microsoft Windows XP [Version 5.1.2600]

Bug Description:
  System property "java.ext.dirs"  returns an invalid path name

  java.ext.dirs=D:\jdk1.6.0\jre\lib\ext;C:\WINDOWS\Sun\Java\lib\ext

  D:\jdk1.6.0\jre\lib\ext  is a valid path.
  But  C:\WINDOWS\Sun\Java\lib\ext  is invalid

Steps to Reproduce (be specific):
  run this program ( SystemPropertyTest )

//----------------------- SystemPropertyTest.java ------------------
import java.util.*;

public class SystemPropertyTest {
  public static void main( String[] arg ){
    Properties properties = System.getProperties();
    String key = "java.ext.dirs";
    String value = (String)properties.get( key );
    System.out.println(key + "=" + value);
  }
}
//-----------------------------------------------------------------