             // watch for page faults
             var modelCursor:IViewCursor = treeData.createCursor();
             if (modelCursor.beforeFirst)
-			{
-				// indicates that an IPE occured on the first item
-				return treeData.length;
-			}
+            {
+                // indicates that an IPE occured on the first item
+                return treeData.length;
+            }
             while (!modelCursor.afterLast)
             {
                 node = modelCursor.current;
                 if (node is XML)
-				{
-					if (firstNode)
-					{	
-						firstNode = false;
-						var parNode:* = node.parent();
-						if (parNode != null)
-						{
-							startTrackUpdates(parNode);
-							childrenMap[parNode] = treeData;
-							parentNode = parNode;
-						}
-					}
-					startTrackUpdates(node);
-				}
-				if (node === null)
-					length += 1;
-				else
-                	length += calculateLength(node, null) + 1;
+                {
+                    if (firstNode)
+                    {   
+                        firstNode = false;
+                        var parNode:* = node.parent();
+                        if (parNode != null)
+                        {
+                            startTrackUpdates(parNode);
+                            childrenMap[parNode] = treeData;
+                            parentNode = parNode;
+                        }
+                    }
+                    startTrackUpdates(node);
+                }
+                if (node === null)
+                    length += 1;
+                else
+                    length += calculateLength(node, null) + 1;
                 modelOffset++;
                 try
                 {

                for (i = 0; i < n; i++)
                {
                    node = ce.items[i].oldValue;
					if (node is XML)
						stopTrackUpdates(node);
                    while (convertedEvent.items[j] != node)
                        j++;
                    convertedEvent.items.splice(j, 1);

                {
                    node = ce.items[i];
                    if (node is XML)
                        stopTrackUpdates(node);
                    getVisibleNodes(node, null, convertedEvent.items);
                }
                currentLength -= convertedEvent.items.length;
