diff --git a/blocks/navigation/navigation.js b/blocks/navigation/navigation.js
index 725c3bc6d8f..df21f0cf18c 100644
--- a/blocks/navigation/navigation.js
+++ b/blocks/navigation/navigation.js
@@ -162,7 +162,7 @@ M.block_navigation.classes.tree.prototype.init_load_ajax = function(e, branch) {
 M.block_navigation.classes.tree.prototype.load_ajax = function(tid, outcome, args) {
     try {
         var object = this.Y.JSON.parse(outcome.responseText);
-        if (this.add_branch(object, args.target.ancestor('LI') ,1)) {
+        if (this.add_branch(object, args.target.ancestor('li') ,1)) {
             if (this.candock) {
                 M.core_dock.resize();
             }
@@ -298,8 +298,10 @@ M.block_navigation.classes.branch.prototype.construct_from_json = function(obj)
  */
 M.block_navigation.classes.branch.prototype.inject_into_dom = function(element) {
 
+    var Y = this.tree.Y;
+
     var isbranch = ((this.expandable !== null || this.haschildren) && this.expansionceiling===null);
-    var branchli = this.tree.Y.Node.create('<li></li>');
+    var branchli = Y.Node.create('<li></li>');
     var branchp = this.tree.Y.Node.create('<p class="tree_item"></p>');
 
     if (isbranch) {
@@ -322,7 +324,8 @@ M.block_navigation.classes.branch.prototype.inject_into_dom = function(element)
     // Prepare the icon, should be an object representing a pix_icon
     var branchicon = false;
     if (this.icon != null && !isbranch) {
-        branchicon = this.tree.Y.Node.create('<img src="'+M.util.image_url(this.icon.pix, this.icon.component)+'" alt="" />');
+        branchicon = Y.Node.create('<img alt="" />');
+        branchicon.setAttribute('src', M.util.image_url(this.icon.pix, this.icon.component));
         branchli.addClass('item_with_icon');
         if (this.icon.alt) {
             branchicon.setAttribute('alt', this.icon.alt);
@@ -343,7 +346,7 @@ M.block_navigation.classes.branch.prototype.inject_into_dom = function(element)
         }
         branchp.append(this.name.replace(/\n/g, '<br />'));
     } else {
-        var branchlink = this.tree.Y.Node.create('<a title="'+this.title+'" href="'+this.link+'"></a>');
+        var branchlink = Y.Node.create('<a title="'+this.title+'" href="'+this.link+'"></a>');
         if (branchicon) {
             branchlink.appendChild(branchicon);
         }
@@ -356,7 +359,7 @@ M.block_navigation.classes.branch.prototype.inject_into_dom = function(element)
 
     branchli.appendChild(branchp);
     if (this.haschildren) {
-        var childrenul = this.tree.Y.Node.create('<ul></ul>');
+        var childrenul = Y.Node.create('<ul></ul>');
         branchli.appendChild(childrenul);
         element.appendChild(branchli);
         return childrenul
diff --git a/lib/ajax/getnavbranch.php b/lib/ajax/getnavbranch.php
index 7c288c96c3e..24e32bfd3d7 100644
--- a/lib/ajax/getnavbranch.php
+++ b/lib/ajax/getnavbranch.php
@@ -43,7 +43,7 @@ try {
     $PAGE->set_context(get_context_instance(CONTEXT_SYSTEM));
 
     // Create a global nav object
-    $navigation = new global_navigation_for_ajax($PAGE);
+    $navigation = new global_navigation_for_ajax($PAGE, $branchtype, $branchid);
 
     if ($instanceid!==null) {
         // Get the db record for the block instance
@@ -68,8 +68,6 @@ try {
     }
 
     // Create a navigation object to use, we can't guarantee PAGE will be complete
-
-    $expandable = $navigation->initialise($branchtype, $branchid);
     if (!isloggedin() || isguestuser()) {
         $navigation->set_expansion_limit(navigation_node::TYPE_COURSE);
     } else {
@@ -102,7 +100,7 @@ if (empty($branch) || $branch->nodetype !== navigation_node::NODETYPE_BRANCH) {
 }
 
 // Prepare an XML converter for the branch
-$converter->set_expandable($expandable);
+$converter->set_expandable($navigation->get_expandable());
 // Set XML headers
 header('Content-type: text/plain');
 // Convert and output the branch as XML
diff --git a/lib/navigationlib.php b/lib/navigationlib.php
index 0282a447769..b618315366f 100644
--- a/lib/navigationlib.php
+++ b/lib/navigationlib.php
@@ -1878,12 +1878,16 @@ class global_navigation extends navigation_node {
     }
 
     public function get($key, $type = null) {
-        $this->initialise();
+        if (!$this->initialised) {
+            $this->initialise();
+        }
         return parent::get($key, $type);
     }
 
     public function find($key, $type) {
-        $this->initialise();
+        if (!$this->initialised) {
+            $this->initialise();
+        }
         return parent::find($key, $type);
     }
 }
@@ -1912,14 +1916,11 @@ class global_navigation_for_ajax extends global_navigation {
     /**
      * Constructs the navigation for use in AJAX request
      */
-    public function __construct($page) {
-        global $SITE;
+    public function __construct($page, $branchtype, $id) {
         $this->page = $page;
         $this->cache = new navigation_cache(NAVIGATION_CACHE_NAME);
         $this->children = new navigation_node_collection();
-        $this->rootnodes = array();
-        $this->rootnodes['site']      = $this->add_course($SITE);
-        $this->rootnodes['courses'] = $this->add(get_string('courses'), null, self::TYPE_ROOTNODE, null, 'courses');
+        $this->initialise($branchtype, $id);
     }
     /**
      * Initialise the navigation given the type and id for the branch to expand.
@@ -1929,11 +1930,16 @@ class global_navigation_for_ajax extends global_navigation {
      * @return array The expandable nodes
      */
     public function initialise($branchtype, $id) {
-        global $CFG, $DB, $PAGE;
+        global $CFG, $DB, $PAGE, $SITE;
 
         if ($this->initialised || during_initial_install()) {
             return $this->expandable;
         }
+        $this->initialised = true;
+
+        $this->rootnodes = array();
+        $this->rootnodes['site']      = $this->add_course($SITE);
+        $this->rootnodes['courses'] = $this->add(get_string('courses'), null, self::TYPE_ROOTNODE, null, 'courses');
 
         // Branchtype will be one of navigation_node::TYPE_*
         switch ($branchtype) {
@@ -2001,6 +2007,10 @@ class global_navigation_for_ajax extends global_navigation {
         $this->find_expandable($this->expandable);
         return $this->expandable;
     }
+
+    public function get_expandable() {
+        return $this->expandable;
+    }
 }
 
 /**