diff --git a/extensions/xforms/nsIInstanceElementPrivate.idl b/extensions/xforms/nsIInstanceElementPrivate.idl
index 1caef76db2f..c3373046e3a 100644
--- a/extensions/xforms/nsIInstanceElementPrivate.idl
+++ b/extensions/xforms/nsIInstanceElementPrivate.idl
@@ -44,7 +44,7 @@ interface nsIDOMElement;
 /**
  * Private interface implemented by the instance element.
  */
-[uuid(446dc7b6-91fc-4de5-b6de-5ac22538ee5e)]
+[uuid(debb24ef-7ba1-4e01-9f62-18106b25c993)]
 interface nsIInstanceElementPrivate : nsISupports
 {
   /**
@@ -54,5 +54,5 @@ interface nsIInstanceElementPrivate : nsISupports
   readonly attribute nsIDOMElement element;
   void backupOriginalDocument();
   void restoreOriginalDocument();
-  void initializeLazyInstance();
+  void initialize();
 };
diff --git a/extensions/xforms/nsXFormsInstanceElement.cpp b/extensions/xforms/nsXFormsInstanceElement.cpp
index 46d60e02545..e576b521d01 100644
--- a/extensions/xforms/nsXFormsInstanceElement.cpp
+++ b/extensions/xforms/nsXFormsInstanceElement.cpp
@@ -63,7 +63,7 @@ NS_IMPL_ISUPPORTS_INHERITED5(nsXFormsInstanceElement,
 
 nsXFormsInstanceElement::nsXFormsInstanceElement()
   : mElement(nsnull)
-  , mAddingChildren(PR_FALSE)
+  , mInitialized(PR_FALSE)
   , mLazy(PR_FALSE)
 {
 }
@@ -87,7 +87,7 @@ NS_IMETHODIMP
 nsXFormsInstanceElement::AttributeSet(nsIAtom *aName,
                                       const nsAString &aNewValue)
 {
-  if (mAddingChildren || mLazy)
+  if (!mInitialized || mLazy)
     return NS_OK;
 
   if (aName == nsXFormsAtoms::src) {
@@ -100,7 +100,7 @@ nsXFormsInstanceElement::AttributeSet(nsIAtom *aName,
 NS_IMETHODIMP
 nsXFormsInstanceElement::AttributeRemoved(nsIAtom *aName)
 {
-  if (mAddingChildren || mLazy)
+  if (!mInitialized || mLazy)
     return NS_OK;
 
   if (aName == nsXFormsAtoms::src) {
@@ -135,51 +135,11 @@ nsXFormsInstanceElement::AttributeRemoved(nsIAtom *aName)
   return NS_OK;
 }
 
-NS_IMETHODIMP
-nsXFormsInstanceElement::BeginAddingChildren()
-{
-  mAddingChildren = PR_TRUE;
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-nsXFormsInstanceElement::DoneAddingChildren()
-{
-  
-  mElement->HasAttributeNS(NS_LITERAL_STRING(NS_NAMESPACE_MOZ_XFORMS_LAZY),
-                           NS_LITERAL_STRING("lazy"), &mLazy);
-  if (!mLazy) {
-    nsCOMPtr<nsIModelElementPrivate> model = GetModel();
-    NS_ENSURE_TRUE(model, NS_ERROR_FAILURE);
-    model->AddInstanceElement(this);
-
-    // By the time this is called, we should be inserted in the document and
-    // have all of our child elements, so this is our first opportunity to
-    // create the instance document.
-  
-    nsAutoString src;
-    mElement->GetAttribute(NS_LITERAL_STRING("src"), src);
-  
-    if (src.IsEmpty()) {
-      // If we don't have a linked external instance, use our inline data.
-      CloneInlineInstance();
-    } else {
-      LoadExternalInstance(src);
-    }
-  }
-
-  mAddingChildren = PR_FALSE;
-  return NS_OK;
-}
-
 NS_IMETHODIMP
 nsXFormsInstanceElement::OnCreated(nsIXTFGenericElementWrapper *aWrapper)
 {
   aWrapper->SetNotificationMask(nsIXTFElement::NOTIFY_ATTRIBUTE_SET |
-                                nsIXTFElement::NOTIFY_ATTRIBUTE_REMOVED |
-                                nsIXTFElement::NOTIFY_PARENT_CHANGED |
-                                nsIXTFElement::NOTIFY_BEGIN_ADDING_CHILDREN |
-                                nsIXTFElement::NOTIFY_DONE_ADDING_CHILDREN);
+                                nsIXTFElement::NOTIFY_ATTRIBUTE_REMOVED);
 
   nsCOMPtr<nsIDOMElement> node;
   aWrapper->GetElementNode(getter_AddRefs(node));
@@ -194,22 +154,6 @@ nsXFormsInstanceElement::OnCreated(nsIXTFGenericElementWrapper *aWrapper)
   return NS_OK;
 }
 
-NS_IMETHODIMP
-nsXFormsInstanceElement::ParentChanged(nsIDOMElement *aNewParent)
-{
-  if (!aNewParent || mAddingChildren || mLazy)
-    return NS_OK;
-
-  // Once we are set up in the DOM, can find the model and make sure that this
-  // instance is on the list of instance elements that model keeps
-  nsCOMPtr<nsIModelElementPrivate> model = GetModel();
-  if (model) {
-    model->AddInstanceElement(this);
-  }
-  
-  return NS_OK;
-}
-
 // nsIInterfaceRequestor
 
 NS_IMETHODIMP
@@ -445,49 +389,73 @@ nsXFormsInstanceElement::GetElement(nsIDOMElement **aElement)
 }
 
 NS_IMETHODIMP
-nsXFormsInstanceElement::InitializeLazyInstance()
+nsXFormsInstanceElement::Initialize()
 {
-  NS_ENSURE_STATE(mElement);
-  if (!mLazy) {
-    mElement->HasAttributeNS(NS_LITERAL_STRING(NS_NAMESPACE_MOZ_XFORMS_LAZY),
-                             NS_LITERAL_STRING("lazy"), &mLazy);
+  if (mInitialized || !mElement) {
+    return NS_OK;
   }
 
-  NS_ENSURE_STATE(mLazy);
+  mInitialized = PR_TRUE;
 
-  nsCOMPtr<nsIDOMDocument> domDoc;
-  mElement->GetOwnerDocument(getter_AddRefs(domDoc));
-  NS_ENSURE_STATE(domDoc);
+  nsCOMPtr<nsIModelElementPrivate> model = GetModel();
+  NS_ENSURE_TRUE(model, NS_ERROR_FAILURE);
+  model->AddInstanceElement(this);
 
-  nsCOMPtr<nsIDOMDOMImplementation> domImpl;
-  nsresult rv = domDoc->GetImplementation(getter_AddRefs(domImpl));
-  NS_ENSURE_SUCCESS(rv, rv);
+  mElement->HasAttributeNS(NS_LITERAL_STRING(NS_NAMESPACE_MOZ_XFORMS_LAZY),
+                           NS_LITERAL_STRING("lazy"), &mLazy);
 
-  nsCOMPtr<nsIDOMDocument> newDoc;
-  rv = domImpl->CreateDocument(EmptyString(), EmptyString(), nsnull,
-                               getter_AddRefs(newDoc));
-  NS_ENSURE_SUCCESS(rv, rv);
+  // Lazy instance
+  if (mLazy) {
+    nsCOMPtr<nsIDOMDocument> domDoc;
+    mElement->GetOwnerDocument(getter_AddRefs(domDoc));
+    NS_ENSURE_STATE(domDoc);
+  
+    nsCOMPtr<nsIDOMDOMImplementation> domImpl;
+    nsresult rv = domDoc->GetImplementation(getter_AddRefs(domImpl));
+    NS_ENSURE_SUCCESS(rv, rv);
+  
+    nsCOMPtr<nsIDOMDocument> newDoc;
+    rv = domImpl->CreateDocument(EmptyString(), EmptyString(), nsnull,
+                                 getter_AddRefs(newDoc));
+    NS_ENSURE_SUCCESS(rv, rv);
+  
+    rv = SetDocument(newDoc);
+    NS_ENSURE_SUCCESS(rv, rv);
+  
+    // Lazy authored instance documents have a root named "instanceData"
+    nsCOMPtr<nsIDOMElement> instanceDataElement;
+    nsCOMPtr<nsIDOMNode> childReturn;
+    rv = mDocument->CreateElementNS(EmptyString(), 
+                                    NS_LITERAL_STRING("instanceData"),
+                                    getter_AddRefs(instanceDataElement));
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = mDocument->AppendChild(instanceDataElement, getter_AddRefs(childReturn));
+    NS_ENSURE_SUCCESS(rv, rv);
+  
+    // I don't know if not being able to create a backup document is worth
+    // failing this function.  Since it probably won't be used often, we'll
+    // let it slide.  But it probably does mean that things are going south
+    // with the browser.
+    domImpl->CreateDocument(EmptyString(), EmptyString(), nsnull,
+                            getter_AddRefs(mOriginalDocument));
+    NS_WARN_IF_FALSE(mOriginalDocument, "Couldn't create mOriginalDocument!!");
+  } else {
+    // Normal instance
 
-  rv = SetDocument(newDoc);
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  // Lazy authored instance documents have a root named "instanceData"
-  nsCOMPtr<nsIDOMElement> instanceDataElement;
-  nsCOMPtr<nsIDOMNode> childReturn;
-  rv = mDocument->CreateElementNS(EmptyString(), 
-                                  NS_LITERAL_STRING("instanceData"),
-                                  getter_AddRefs(instanceDataElement));
-  NS_ENSURE_SUCCESS(rv, rv);
-  rv = mDocument->AppendChild(instanceDataElement, getter_AddRefs(childReturn));
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  // I don't know if not being able to create a backup document is worth
-  // failing this function.  Since it probably won't be used often, we'll
-  // let it slide.  But it probably does mean that things are going south
-  // with the browser.
-  domImpl->CreateDocument(EmptyString(), EmptyString(), nsnull,
-                          getter_AddRefs(mOriginalDocument));
-  NS_WARN_IF_FALSE(mOriginalDocument, "Couldn't create mOriginalDocument!!");
+    // By the time this is called, we should be inserted in the document and
+    // have all of our child elements, so this is our first opportunity to
+    // create the instance document.
+  
+    nsAutoString src;
+    mElement->GetAttribute(NS_LITERAL_STRING("src"), src);
+  
+    if (src.IsEmpty()) {
+      // If we don't have a linked external instance, use our inline data.
+      CloneInlineInstance();
+    } else {
+      LoadExternalInstance(src);
+    }
+  }
 
   return NS_OK;
 }
diff --git a/extensions/xforms/nsXFormsInstanceElement.h b/extensions/xforms/nsXFormsInstanceElement.h
index f0531da5a88..81a2e364c38 100644
--- a/extensions/xforms/nsXFormsInstanceElement.h
+++ b/extensions/xforms/nsXFormsInstanceElement.h
@@ -75,10 +75,7 @@ public:
   NS_IMETHOD OnDestroyed();
   NS_IMETHOD AttributeSet(nsIAtom *aName, const nsAString &aNewValue);
   NS_IMETHOD AttributeRemoved(nsIAtom *aName);
-  NS_IMETHOD BeginAddingChildren();
-  NS_IMETHOD DoneAddingChildren();
   NS_IMETHOD OnCreated(nsIXTFGenericElementWrapper *aWrapper);
-  NS_IMETHOD ParentChanged(nsIDOMElement *aNewParent);
 
   nsXFormsInstanceElement() NS_HIDDEN;
 
@@ -92,7 +89,7 @@ private:
   nsCOMPtr<nsIDOMDocument>    mOriginalDocument;
   nsIDOMElement              *mElement;
   nsCOMPtr<nsIStreamListener> mListener;
-  PRBool                      mAddingChildren;
+  PRBool                      mInitialized;
   PRBool                      mLazy;
   nsCOMPtr<nsIChannel>        mChannel;
 };
diff --git a/extensions/xforms/nsXFormsModelElement.cpp b/extensions/xforms/nsXFormsModelElement.cpp
index 1b4725a29eb..9cbcca4c594 100644
--- a/extensions/xforms/nsXFormsModelElement.cpp
+++ b/extensions/xforms/nsXFormsModelElement.cpp
@@ -260,6 +260,7 @@ nsXFormsModelElement::nsXFormsModelElement()
     mPendingInstanceCount(0),
     mDocumentLoaded(PR_FALSE),
     mNeedsRefresh(PR_FALSE),
+    mInstancesInitialized(PR_FALSE),
     mInstanceDocuments(nsnull),
     mLazyModel(PR_FALSE)
 {
@@ -346,6 +347,36 @@ nsXFormsModelElement::DocumentChanged(nsIDOMDocument* aNewDocument)
 NS_IMETHODIMP
 nsXFormsModelElement::DoneAddingChildren()
 {
+  return InitializeInstances();
+}
+
+nsresult
+nsXFormsModelElement::InitializeInstances()
+{
+  if (mInstancesInitialized || !mElement) {
+    return NS_OK;
+  }
+
+  mInstancesInitialized = PR_TRUE;
+
+  nsCOMPtr<nsIDOMNodeList> children;
+  mElement->GetChildNodes(getter_AddRefs(children));
+
+  PRUint32 childCount = 0;
+  if (children) {
+    children->GetLength(&childCount);
+  }
+
+  for (PRUint32 i = 0; i < childCount; ++i) {
+    nsCOMPtr<nsIDOMNode> child;
+    children->Item(i, getter_AddRefs(child));
+    if (nsXFormsUtils::IsXFormsElement(child, NS_LITERAL_STRING("instance"))) {
+      nsCOMPtr<nsIInstanceElementPrivate> instance(do_QueryInterface(child));
+      if (instance) {
+        instance->Initialize();
+      }
+    }
+  }
 
   // (XForms 4.2.1)
   // 1. load xml schemas
@@ -427,6 +458,9 @@ nsXFormsModelElement::DoneAddingChildren()
   PRUint32 instCount;
   mInstanceDocuments->GetLength(&instCount);
   if (!instCount) {
+#ifdef DEBUG
+    printf("Creating lazy instance\n");
+#endif
     nsCOMPtr<nsIDOMDocument> domDoc;
     mElement->GetOwnerDocument(getter_AddRefs(domDoc));
     nsCOMPtr<nsIDOMDocumentXBL> xblDoc(do_QueryInterface(domDoc));
@@ -437,8 +471,6 @@ nsXFormsModelElement::DoneAddingChildren()
       NS_ENSURE_SUCCESS(rv, rv);
 
       mInstanceDocuments->GetLength(&instCount);
-      NS_WARN_IF_FALSE(instCount == 1,
-                       "Installing lazy instance didn't succeed!");
 
       nsCOMPtr<nsIDOMNodeList> list;
       xblDoc->GetAnonymousNodes(mElement, getter_AddRefs(list));
@@ -454,7 +486,7 @@ nsXFormsModelElement::DoneAddingChildren()
           nsCOMPtr<nsIInstanceElementPrivate> instance =
             do_QueryInterface(item);
           if (instance) {
-            rv = instance->InitializeLazyInstance();
+            rv = instance->Initialize();
             NS_ENSURE_SUCCESS(rv, rv);
 
             mLazyModel = PR_TRUE;
@@ -463,6 +495,7 @@ nsXFormsModelElement::DoneAddingChildren()
         }
       }
     }
+    NS_WARN_IF_FALSE(mLazyModel, "Installing lazy instance didn't succeed!");
   }
 
   // (XForms 4.2.1 - cont)
@@ -893,6 +926,12 @@ nsXFormsModelElement::HandleEvent(nsIDOMEvent* aEvent)
   if (!type.EqualsLiteral("DOMContentLoaded"))
     return NS_OK;
 
+  if (!mInstancesInitialized) {
+    // XXX This is for Bug 308106. In Gecko 1.8 DoneAddingChildren is not
+    //     called in XUL if the element doesn't have any child nodes.
+    InitializeInstances();
+  }
+
   mDocumentLoaded = PR_TRUE;
 
   // dispatch xforms-model-construct, xforms-rebuild, xforms-recalculate,
diff --git a/extensions/xforms/nsXFormsModelElement.h b/extensions/xforms/nsXFormsModelElement.h
index 2af15abbd43..161c6542cc6 100644
--- a/extensions/xforms/nsXFormsModelElement.h
+++ b/extensions/xforms/nsXFormsModelElement.h
@@ -178,6 +178,8 @@ private:
   /** Initializes the MIPs on all form controls */
   NS_HIDDEN_(nsresult) InitializeControls();
 
+  NS_HIDDEN_(nsresult) InitializeInstances();
+
   NS_HIDDEN_(nsresult) ProcessBindElements();
   NS_HIDDEN_(nsresult) FinishConstruction();
   NS_HIDDEN_(nsresult) ConstructDone();
@@ -253,6 +255,9 @@ private:
   // xforms-revalidate yet
   PRBool mNeedsRefresh;
 
+  // This flag indicates whether instance elements have been initialized
+  PRBool mInstancesInitialized;
+
   /**
    * All instance documents contained by this model, including lazy-authored
    * instance documents.