diff --git a/widget/src/xpwidgets/nsTreeView.cpp b/widget/src/xpwidgets/nsTreeView.cpp
index 34523d214e8..e8b334c6624 100644
--- a/widget/src/xpwidgets/nsTreeView.cpp
+++ b/widget/src/xpwidgets/nsTreeView.cpp
@@ -71,11 +71,6 @@ nsTreeView::nsTreeView() : nsITreeView(), nsDataModelWidget()
 {
   NS_INIT_REFCNT();
   mDataModel = nsnull;
-  mColumnBarRect.SetRect(0,0,0,0);
-  mTitleBarRect.SetRect(0,0,0,0);
-  mControlStripRect.SetRect(0,0,0,0);
-  mTreeRect.SetRect(0,0,0,0);
-  mCachedMoveRect.SetRect(0,0,0,0);
   mMouseDown = PR_FALSE;
   mMouseDragging = PR_FALSE;
   mDraggingColumnHeader = PR_FALSE;
@@ -155,7 +150,7 @@ nsEventStatus nsTreeView::HandleEvent(nsGUIEvent *aEvent)
 		PaintColumnBar(ctx, r);
 
 		// Paint the tree.
-		PaintTreeLines(ctx, r);
+		PaintTreeRows(ctx, r);
 	}
 	ctx->CopyOffScreenBits(ds, 0, 0, rect, NS_COPYBITS_USE_SOURCE_CLIP_REGION);
     ctx->DestroyDrawingSurface(ds);
@@ -601,7 +596,7 @@ void nsTreeView::PaintPusherArrow(nsIRenderingContext* drawCtx,
 	}
 }
 					
-void nsTreeView::PaintTreeLines(nsIRenderingContext* drawCtx, 
+void nsTreeView::PaintTreeRows(nsIRenderingContext* drawCtx, 
 								nsRect& rect)
 {
 	// The fun part. Painting of the individual lines of the tree.
@@ -619,7 +614,7 @@ void nsTreeView::PaintTreeLines(nsIRenderingContext* drawCtx,
 
 	while (pItem && yPosition < rect.y + rect.height)
 	{
-		PaintTreeLine(drawCtx, pItem, yPosition); 
+		PaintTreeRow(drawCtx, pItem, yPosition); 
 		n++;
 		pItem = (nsTreeItem*)mDataModel->GetNthItem(n);
 	}
@@ -634,7 +629,7 @@ void nsTreeView::PaintTreeLines(nsIRenderingContext* drawCtx,
 	}
 }
 
-void nsTreeView::PaintTreeLine(nsIRenderingContext* drawCtx, nsTreeItem* pItem, int& yPosition)
+void nsTreeView::PaintTreeRow(nsIRenderingContext* drawCtx, nsTreeItem* pItem, int& yPosition)
 {
 	// Determine the height of this tree line.  It is going to be the max of
 	// three objects: the trigger image, the icon, and the font height.
diff --git a/widget/src/xpwidgets/nsTreeView.h b/widget/src/xpwidgets/nsTreeView.h
index 6f0c97222a7..526f781ccfe 100644
--- a/widget/src/xpwidgets/nsTreeView.h
+++ b/widget/src/xpwidgets/nsTreeView.h
@@ -29,10 +29,6 @@
 class nsIImageGroup;
 class nsIImage;
 
-// Constants
-const int cIndentAmount = 19;
-const int cIconMargin = 2;
-const int cMinColumnWidth = 30;
 
 //------------------------------------------------------------
 // A tree view consists of several components: a title bar, a control strip,
@@ -46,7 +42,6 @@ const int cMinColumnWidth = 30;
 
 class nsTreeView : public nsITreeView,
 				   public nsDataModelWidget
-                  
 {
 public:
     nsTreeView();
@@ -67,6 +62,9 @@ public:
                                 nsWidgetInitData *aInitData);
 
 protected:
+
+	enum { cIndentAmount = 19, cIconMargin = 2, cMinColumnWidth = 30 };
+
 	// These functions are all used in painting.
 	void PaintTitleBar(nsIRenderingContext* drawCtx, 
 					   nsRect& rect);
@@ -83,10 +81,9 @@ protected:
 	void PaintPusherArrow(nsIRenderingContext* drawCtx,
 								  PRBool isLeftArrow, int left, int width);
 
-	// These functions are used to paint the lines in the tree.
-	void PaintTreeLines(nsIRenderingContext* drawCtx, 
-					    nsRect& rect);
-	void PaintTreeLine(nsIRenderingContext* drawCtx, nsTreeItem* pItem, int& yPosition);
+	// These functions are used to paint the rows in the tree.
+	void PaintTreeRows(nsIRenderingContext* drawCtx, nsRect& rect);
+	void PaintTreeRow(nsIRenderingContext* drawCtx, nsTreeItem* pItem, int& yPosition);
 
 	// General function for painting a background image.
 	void PaintBackgroundImage(nsIRenderingContext* drawCtx, 
@@ -138,7 +135,12 @@ protected:
 	PRBool mDraggingColumnEdge; // Whether or not we're dragging a column edge.
 
 	PRBool mDraggingColumnHeader;	// Whether or not we're dragging a column header
-	
+
+private:
+	// tree views are widgets which exist in one-to-one correspondance with objects on
+	// the screen. Copying them does not make sense, so we outlaw it explicitly.
+	nsTreeView ( const nsTreeView & ) ;					// DON'T IMPLEMENT
+	nsTreeView & operator= ( const nsTreeView & );		// DON'T IMPLEMENT
 };
 
-#endif /* nsToolbar_h___ */
+#endif /* nsTreeView_h___ */