Index: src/components/org/apache/jmeter/control/IncludeController.java
===================================================================
--- src/components/org/apache/jmeter/control/IncludeController.java	(revision 451872)
+++ src/components/org/apache/jmeter/control/IncludeController.java	(working copy)
@@ -20,12 +20,13 @@
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.InputStream;
-import java.util.Iterator;
-import java.util.LinkedList;
+import java.util.*;
 
 import org.apache.jmeter.save.SaveService;
 import org.apache.jmeter.testelement.TestElement;
+import org.apache.jmeter.testelement.TestPlan;
 import org.apache.jmeter.util.JMeterUtils;
+import org.apache.jmeter.config.Arguments;
 import org.apache.jorphan.collections.HashTree;
 import org.apache.jorphan.logging.LoggingManager;
 import org.apache.jorphan.util.JOrphanUtils;
@@ -99,8 +100,45 @@
      * The way ReplaceableController works is clone is called first,
      * followed by replace(HashTree) and finally getReplacement().
      */
-    public HashTree getReplacementSubTree() {
-        return SUBTREE;
+    public HashTree getReplacementSubTree()
+    {
+		/**
+         * The IncludeController did not work before. Because everything needs to be
+         * placed under a TestPlan in the IncludeController, when JMeter traverses the
+         * subtree of the IncludeController before running, it only adds nodes which are
+         * instanceOf Sampler or Controller. Because TestPlan is not in these catergories,
+         * JMeter just skips it and that is why the IncludeController does not work.
+         *
+         * The solution is to only return the subtree under the TestPlan when JMeter asks
+         * for the replacement subtree for the reason mentioned above. As the TestPlan is
+         * skipped, we need to make a copy for all the user defined variables from the TestPlan.
+         * Because the user defined variable controller works anywhere in the tree, so it just
+         * needs to copy them to somewhere in the tree (I choose to copy them as a child
+         * under the TestPlan).
+        */
+        
+		Map args = ((TestPlan) this.SUB).getUserDefinedVariables();
+        Iterator iter = args.entrySet().iterator();
+        Arguments arguments = null;
+
+        while (iter.hasNext())
+        {
+            if (arguments == null)
+            {
+                arguments = new Arguments();
+                // have to enable the TestElement explicitly, or it will be removed
+                arguments.setProperty(TestElement.ENABLED, "true");
+            }
+            Map.Entry entry = (Map.Entry)iter.next();
+            arguments.addArgument((String)entry.getKey(), (String)entry.getValue(), "=");
+        }
+
+        // Get the subtree under the TestPlan
+        HashTree children = SUBTREE.getTree(this.SUB);
+        if (arguments != null)
+            children.add(arguments);
+
+        return children;
     }
 
     /**