Index: src/java/org/apache/ivy/core/settings/IvySettings.java
===================================================================
--- src/java/org/apache/ivy/core/settings/IvySettings.java	(revision 902503)
+++ src/java/org/apache/ivy/core/settings/IvySettings.java	(working copy)
@@ -723,6 +723,9 @@
 
     public void setDefaultResolver(String resolverName) {
         checkResolverName(resolverName);
+        if (resolverName != null && !resolverName.equals(defaultResolverName)) {
+            defaultResolver = null;
+        }
         defaultResolverName = resolverName;
     }
 
Index: test/java/org/apache/ivy/core/settings/IvySettingsTest.java
===================================================================
--- test/java/org/apache/ivy/core/settings/IvySettingsTest.java	(revision 0)
+++ test/java/org/apache/ivy/core/settings/IvySettingsTest.java	(revision 0)
@@ -0,0 +1,48 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+package org.apache.ivy.core.settings;
+
+import java.io.IOException;
+import java.text.ParseException;
+
+import junit.framework.TestCase;
+
+import org.apache.ivy.Ivy;
+import org.apache.ivy.plugins.resolver.DependencyResolver;
+
+public class IvySettingsTest extends TestCase {
+
+    public void testChangeDefaultResolver() throws ParseException, IOException {
+        Ivy ivy = new Ivy();
+        ivy.configureDefault();
+
+        IvySettings settings = ivy.getSettings();
+        DependencyResolver defaultResolver = settings.getDefaultResolver();
+        
+        assertNotNull(defaultResolver);
+        assertEquals("default", defaultResolver.getName());
+        assertSame("default resolver cached", defaultResolver, settings.getDefaultResolver());
+        
+        settings.setDefaultResolver("public");
+        DependencyResolver newDefault = settings.getDefaultResolver();
+        assertNotNull(newDefault);
+        assertNotSame("default resolver has changed", defaultResolver, newDefault);
+        assertEquals("resolver changed successfully", "public", newDefault.getName());
+    }
+    
+}