diff --git a/xpfe/components/directory/nsDirectoryViewer.cpp b/xpfe/components/directory/nsDirectoryViewer.cpp
index 4a12ebdb718e..d9e4820f268f 100644
--- a/xpfe/components/directory/nsDirectoryViewer.cpp
+++ b/xpfe/components/directory/nsDirectoryViewer.cpp
@@ -16,6 +16,8 @@
 */
 
 #include "nsDirectoryViewer.h"
+#include "nsArray.h"
+#include "nsArrayUtils.h"
 #include "nsIDirIndex.h"
 #include "nsIDocShell.h"
 #include "jsapi.h"
@@ -26,7 +28,6 @@
 #include "nsRDFCID.h"
 #include "rdf.h"
 #include "nsIServiceManager.h"
-#include "nsISupportsArray.h"
 #include "nsIXPConnect.h"
 #include "nsEnumeratorUtils.h"
 #include "nsString.h"
@@ -590,8 +591,7 @@ nsHTTPIndex::CommonInit()
     rv = mDirRDF->GetLiteral(u"false", getter_AddRefs(kFalseLiteral));
     if (NS_FAILED(rv)) return(rv);
 
-    rv = NS_NewISupportsArray(getter_AddRefs(mConnectionList));
-    if (NS_FAILED(rv)) return(rv);
+    mConnectionList = nsArray::Create();
 
     // note: don't register DS here
     return rv;
@@ -848,11 +848,12 @@ nsHTTPIndex::GetTargets(nsIRDFResource *aSource, nsIRDFResource *aProperty, bool
         // by using a global connection list and an immediately-firing timer
 		if (doNetworkRequest && mConnectionList)
 		{
-		    int32_t connectionIndex = mConnectionList->IndexOf(aSource);
-		    if (connectionIndex < 0)
+		    uint32_t connectionIndex;
+                    nsresult idx_rv = mConnectionList->IndexOf(0, aSource, &connectionIndex);
+		    if (NS_FAILED(idx_rv))
 		    {
     		    // add aSource into list of connections to make
-	    	    mConnectionList->AppendElement(aSource);
+	    	    mConnectionList->AppendElement(aSource, /*weak =*/ false);
 
                 // if we don't have a timer about to fire, create one
                 // which should fire as soon as possible (out-of-band)
@@ -883,14 +884,13 @@ nsHTTPIndex::AddElement(nsIRDFResource *parent, nsIRDFResource *prop, nsIRDFNode
 
     if (!mNodeList)
     {
-        rv = NS_NewISupportsArray(getter_AddRefs(mNodeList));
-        if (NS_FAILED(rv)) return(rv);
+        mNodeList = nsArray::Create();
     }
 
     // order required: parent, prop, then child
-    mNodeList->AppendElement(parent);
-    mNodeList->AppendElement(prop);
-    mNodeList->AppendElement(child);
+    mNodeList->AppendElement(parent, /*weak =*/ false);
+    mNodeList->AppendElement(prop, /*weak =*/ false);
+    mNodeList->AppendElement(child, /*weak = */ false);
 
 	if (!mTimer)
 	{
@@ -918,20 +918,16 @@ nsHTTPIndex::FireTimer(nsITimer* aTimer, void* aClosure)
   uint32_t numItems = 0;
   if (httpIndex->mConnectionList)
   {
-    httpIndex->mConnectionList->Count(&numItems);
+    httpIndex->mConnectionList->GetLength(&numItems);
     if (numItems > 0)
     {
-      nsCOMPtr<nsISupports> isupports;
-      httpIndex->mConnectionList->GetElementAt((uint32_t)0, getter_AddRefs(isupports));
-      httpIndex->mConnectionList->RemoveElementAt((uint32_t)0);
-
-      nsCOMPtr<nsIRDFResource> source;
-      if (isupports)
-        aSource = do_QueryInterface(isupports);
+      nsCOMPtr<nsIRDFResource> source =
+          do_QueryElementAt(httpIndex->mConnectionList, 0);
+      httpIndex->mConnectionList->RemoveElementAt(0);
 
       nsXPIDLCString uri;
-      if (aSource) {
-        httpIndex->GetDestination(aSource, uri);
+      if (source) {
+        httpIndex->GetDestination(source, uri);
       }
 
       if (!uri) {
@@ -960,7 +956,7 @@ nsHTTPIndex::FireTimer(nsITimer* aTimer, void* aClosure)
 
   if (httpIndex->mNodeList)
   {
-    httpIndex->mNodeList->Count(&numItems);
+    httpIndex->mNodeList->GetLength(&numItems);
     if (numItems > 0)
     {
       // account for order required: src, prop, then target
@@ -971,23 +967,14 @@ nsHTTPIndex::FireTimer(nsITimer* aTimer, void* aClosure)
       int32_t loop;
       for (loop=0; loop<(int32_t)numItems; loop++)
       {
-        nsCOMPtr<nsISupports> isupports;
-        httpIndex->mNodeList->GetElementAt((uint32_t)0, getter_AddRefs(isupports));
-        httpIndex->mNodeList->RemoveElementAt((uint32_t)0);
-        nsCOMPtr<nsIRDFResource> src;
-        if (isupports)
-          src = do_QueryInterface(isupports);
-        httpIndex->mNodeList->GetElementAt((uint32_t)0, getter_AddRefs(isupports));
-        httpIndex->mNodeList->RemoveElementAt((uint32_t)0);
-        nsCOMPtr<nsIRDFResource> prop;
-        if (isupports)
-          prop = do_QueryInterface(isupports);
+        nsCOMPtr<nsIRDFResource> src = do_QueryElementAt(httpIndex->mNodeList, 0);
+        httpIndex->mNodeList->RemoveElementAt(0);
 
-        httpIndex->mNodeList->GetElementAt((uint32_t)0, getter_AddRefs(isupports));
-        httpIndex->mNodeList->RemoveElementAt((uint32_t)0);
-        nsCOMPtr<nsIRDFNode> target;
-        if (isupports)
-          target = do_QueryInterface(isupports);
+        nsCOMPtr<nsIRDFResource> prop = do_QueryElementAt(httpIndex->mNodeList, 0);
+        httpIndex->mNodeList->RemoveElementAt(0);
+
+        nsCOMPtr<nsIRDFNode> target = do_QueryElementAt(httpIndex->mNodeList, 0);
+        httpIndex->mNodeList->RemoveElementAt(0);
 
         if (src && prop && target)
         {
@@ -1008,7 +995,7 @@ nsHTTPIndex::FireTimer(nsITimer* aTimer, void* aClosure)
   // check both lists to see if the timer needs to continue firing
   if (httpIndex->mConnectionList)
   {
-    httpIndex->mConnectionList->Count(&numItems);
+    httpIndex->mConnectionList->GetLength(&numItems);
     if (numItems > 0)
     {
       refireTimer = true;
@@ -1018,9 +1005,10 @@ nsHTTPIndex::FireTimer(nsITimer* aTimer, void* aClosure)
       httpIndex->mConnectionList->Clear();
     }
   }
+
   if (httpIndex->mNodeList)
   {
-    httpIndex->mNodeList->Count(&numItems);
+    httpIndex->mNodeList->GetLength(&numItems);
     if (numItems > 0)
     {
       refireTimer = true;
diff --git a/xpfe/components/directory/nsDirectoryViewer.h b/xpfe/components/directory/nsDirectoryViewer.h
index 2bb4297bbea9..05b68f1b6d95 100644
--- a/xpfe/components/directory/nsDirectoryViewer.h
+++ b/xpfe/components/directory/nsDirectoryViewer.h
@@ -6,6 +6,7 @@
 #ifndef nsdirectoryviewer__h____
 #define nsdirectoryviewer__h____
 
+#include "nsCOMPtr.h"
 #include "nsIStreamListener.h"
 #include "nsIContentViewer.h"
 #include "nsIHTTPIndex.h"
@@ -14,7 +15,6 @@
 #include "nsIRDFLiteral.h"
 #include "nsIDocumentLoaderFactory.h"
 #include "nsITimer.h"
-#include "nsISupportsArray.h"
 #include "nsXPIDLString.h"
 #include "nsIDirIndexListener.h"
 #include "nsIFTPChannel.h"
@@ -22,6 +22,8 @@
 #include "nsIInterfaceRequestor.h"
 #include "nsIURI.h"
 
+class nsIMutableArray;
+
 class nsDirectoryViewerFactory : public nsIDocumentLoaderFactory
 {
 public:
@@ -70,8 +72,8 @@ protected:
     // an OnStartRequest() notification
 
     nsCOMPtr<nsIRDFDataSource>   mInner;
-    nsCOMPtr<nsISupportsArray>   mConnectionList;
-    nsCOMPtr<nsISupportsArray>   mNodeList;
+    nsCOMPtr<nsIMutableArray>    mConnectionList;
+    nsCOMPtr<nsIMutableArray>    mNodeList;
     nsCOMPtr<nsITimer>           mTimer;
     nsCOMPtr<nsIDirIndexParser>  mParser;
     nsCString mBaseURL;