diff --git a/mozilla/extensions/xforms/nsXFormsInstanceElement.cpp b/mozilla/extensions/xforms/nsXFormsInstanceElement.cpp
index a9ace90b5dc..3a51371b276 100644
--- a/mozilla/extensions/xforms/nsXFormsInstanceElement.cpp
+++ b/mozilla/extensions/xforms/nsXFormsInstanceElement.cpp
@@ -498,16 +498,50 @@ nsXFormsInstanceElement::CloneInlineInstance()
     temp->GetNextSibling(getter_AddRefs(child));
   }
 
-  if (child) {
-    nsCOMPtr<nsIDOMNode> newNode;
-    rv = mDocument->ImportNode(child, PR_TRUE, getter_AddRefs(newNode));
-    NS_ENSURE_SUCCESS(rv, rv);
-
-    nsCOMPtr<nsIDOMNode> nodeReturn;
-    rv = mDocument->AppendChild(newNode, getter_AddRefs(nodeReturn));
-    NS_WARN_IF_FALSE(NS_SUCCEEDED(rv), "failed to append root instance node");
+  // There needs to be a child element, or it is not a valid XML document
+  if (!child) {
+    nsXFormsUtils::ReportError(NS_LITERAL_STRING("inlineInstanceNoChildError"),
+                               mElement);
+    nsCOMPtr<nsIModelElementPrivate> model(GetModel());
+    nsCOMPtr<nsIDOMNode> modelNode(do_QueryInterface(model));
+    nsXFormsUtils::DispatchEvent(modelNode, eEvent_LinkException);
+    nsXFormsUtils::HandleFatalError(mElement,
+                                    NS_LITERAL_STRING("XFormsLinkException"));
+    return NS_ERROR_FAILURE;
   }
 
+  // Check for siblings to first child element node. This is an error, since
+  // the inline content is then not a well-formed XML document.
+  nsCOMPtr<nsIDOMNode> sibling;
+  child->GetNextSibling(getter_AddRefs(sibling));
+  while (sibling) {
+    PRUint16 nodeType;
+    sibling->GetNodeType(&nodeType);
+
+    if (nodeType == nsIDOMNode::ELEMENT_NODE) {
+      nsXFormsUtils::ReportError(NS_LITERAL_STRING("inlineInstanceMultipleElementsError"),
+                                 mElement);
+      nsCOMPtr<nsIModelElementPrivate> model(GetModel());
+      nsCOMPtr<nsIDOMNode> modelNode(do_QueryInterface(model));
+      nsXFormsUtils::DispatchEvent(modelNode, eEvent_LinkException);
+      nsXFormsUtils::HandleFatalError(mElement,
+                                      NS_LITERAL_STRING("XFormsLinkException"));
+      return NS_ERROR_FAILURE;
+    }
+
+    temp.swap(sibling);
+    temp->GetNextSibling(getter_AddRefs(sibling));
+  }
+
+  // Clone and insert content into new document
+  nsCOMPtr<nsIDOMNode> newNode;
+  rv = mDocument->ImportNode(child, PR_TRUE, getter_AddRefs(newNode));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIDOMNode> nodeReturn;
+  rv = mDocument->AppendChild(newNode, getter_AddRefs(nodeReturn));
+  NS_WARN_IF_FALSE(NS_SUCCEEDED(rv), "failed to append root instance node");
+
   return rv;
 }
 
diff --git a/mozilla/extensions/xforms/nsXFormsModelElement.cpp b/mozilla/extensions/xforms/nsXFormsModelElement.cpp
index 3d762e152ad..b051c514320 100644
--- a/mozilla/extensions/xforms/nsXFormsModelElement.cpp
+++ b/mozilla/extensions/xforms/nsXFormsModelElement.cpp
@@ -761,14 +761,15 @@ nsXFormsModelElement::InitializeInstances()
     children->GetLength(&childCount);
   }
 
+  nsresult rv;
   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();
-      }
+      NS_ENSURE_STATE(instance);
+      rv = instance->Initialize();
+      NS_ENSURE_SUCCESS(rv, rv);
     }
   }
 
@@ -793,7 +794,7 @@ nsXFormsModelElement::InitializeInstances()
     mSchemaTotal = schemas.Count();
 
     for (PRInt32 i=0; i<mSchemaTotal; ++i) {
-      nsresult rv = NS_OK;
+      rv = NS_OK;
       nsCOMPtr<nsIURI> newURI;
       NS_NewURI(getter_AddRefs(newURI), *schemas[i], nsnull, baseURI);
       nsCOMPtr<nsIURL> newURL = do_QueryInterface(newURI);
diff --git a/mozilla/extensions/xforms/nsXFormsModule.cpp b/mozilla/extensions/xforms/nsXFormsModule.cpp
index f403e825d17..224e65e5267 100644
--- a/mozilla/extensions/xforms/nsXFormsModule.cpp
+++ b/mozilla/extensions/xforms/nsXFormsModule.cpp
@@ -60,6 +60,10 @@ RegisterXFormsModule(nsIComponentManager *aCompMgr,
                      const char *aComponentType,
                      const nsModuleComponentInfo *aInfo)
 {
+#ifdef DEBUG
+  printf("XFORMS Module: Registering\n");
+#endif
+
   nsCOMPtr<nsICategoryManager> catman =
     do_GetService(NS_CATEGORYMANAGER_CONTRACTID);
 
@@ -93,6 +97,10 @@ UnregisterXFormsModule(nsIComponentManager *aCompMgr,
                        const char *aRegistryLocation,
                        const nsModuleComponentInfo *aInfo)
 {
+#ifdef DEBUG
+  printf("XFORMS Module: Unregistering\n");
+#endif
+
   nsCOMPtr<nsICategoryManager> catman =
     do_GetService(NS_CATEGORYMANAGER_CONTRACTID);
 
diff --git a/mozilla/extensions/xforms/resources/locale/en-US/xforms.properties b/mozilla/extensions/xforms/resources/locale/en-US/xforms.properties
index acaef44fe47..db91bbc9e2e 100644
--- a/mozilla/extensions/xforms/resources/locale/en-US/xforms.properties
+++ b/mozilla/extensions/xforms/resources/locale/en-US/xforms.properties
@@ -72,6 +72,8 @@ instanceNotFound     = XForms Error (33): Could not find instance with id == '%S
 defInstanceNotFound  = XForms Error (34): Could not find default instance
 MDGLoopError         = XForms Error (35): There are loops in the bindings of the model!
 invalidExtFunction   = XForms Error (36): Non-existant extension functions listed in this model's function attribute
+inlineInstanceNoChildError = XForms Error (37): Inline instance has no child elements. This is illegal.
+inlineInstanceMultipleElementsError = XForms Error (38): Inline instance has multiple child elements. This is illegal.
 
 # Warning Messages:
 warnSOAP             = XForms Warning (1): You are using the SOAP post feature, which is an experimental feature! Beware that the functionality might change, and forms may stop working at any time.