=== modified file dhis-2/dhis-web/dhis-web-commons/src/main/java/org/hisp/dhis/security/filter/UserAuditLogoutFilter.java
--- dhis-2/dhis-web/dhis-web-commons/src/main/java/org/hisp/dhis/security/filter/UserAuditLogoutFilter.java	2010-05-03 13:44:59 +0000
+++ dhis-2/dhis-web/dhis-web-commons/src/main/java/org/hisp/dhis/security/filter/UserAuditLogoutFilter.java	2010-10-04 05:32:55 +0000
@@ -27,6 +27,7 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+import java.io.IOException;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
@@ -41,6 +42,7 @@
 public class UserAuditLogoutFilter
     implements LogoutHandler
 {
+
     private UserAuditService userAuditService;
 
     public void setUserAuditService( UserAuditService userAuditService )
@@ -48,10 +50,21 @@
         this.userAuditService = userAuditService;
     }
 
+    @Override
     public void logout( HttpServletRequest request, HttpServletResponse response, Authentication authentication )
     {
-        String username = (( UserDetails ) authentication.getPrincipal()).getUsername();
-        
-        userAuditService.registerLogout( username );
+        if ( authentication != null )
+        {
+            String username = ( (UserDetails) authentication.getPrincipal() ).getUsername();
+            userAuditService.registerLogout( username );
+        } else
+        {
+            try
+            {
+                response.sendRedirect( request.getContextPath() );
+            } catch ( IOException ex )
+            {
+            }
+        }
     }
 }