--- a/Tools__ViewTreeApplication.st	Thu Mar 26 11:20:01 2015 +0100
+++ b/Tools__ViewTreeApplication.st	Mon May 04 16:41:15 2015 +0200
@@ -1,3 +1,5 @@
+"{ Encoding: utf8 }"
+
 "
  COPYRIGHT (c) 2007 by eXept Software AG
               All Rights Reserved
@@ -2900,18 +2902,29 @@
 !ViewTreeInspectorApplication::ViewTreeItem methodsFor:'operations update'!
 
 updateChildren
-    |list|
-
-    self do:[:el|
-        el exists ifTrue:[
-            el updateChildren.
-        ] ifFalse:[
-            list isNil ifTrue:[list := OrderedCollection new].
-            list add:el.
-        ]
-    ].
-    list notNil ifTrue:[
-        list do:[:el| self remove:el ].
+    |queue|
+
+    queue := OrderedCollection new.
+    queue add:self.
+
+    self criticalDo:[
+        [queue notEmpty] whileTrue:[
+            |toRemove  elProcessed|
+
+            elProcessed := queue removeFirst.
+            toRemove := nil.
+            elProcessed nonCriticalDo:[:el|
+                el exists ifTrue:[
+                    queue add:el.
+                ] ifFalse:[
+                    toRemove isNil ifTrue:[toRemove := OrderedCollection new].
+                    toRemove add:el.
+                ]
+            ].
+            toRemove notNil ifTrue:[
+                toRemove do:[:el| self remove:el ].
+            ].
+        ].
     ].
 !