--- a/Tools_HierarchicalClassList.st	Tue Mar 28 19:44:59 2006 +0200
+++ b/Tools_HierarchicalClassList.st	Tue Mar 28 19:45:33 2006 +0200
@@ -86,14 +86,24 @@
     ^ topClassHolder
 !
 
-topClassHolder:aTriggerValue
+topClassHolder:aValueHolder
+    |oldTopClass newTopClass|
+
+    oldTopClass := topClassHolder value.
+
     topClassHolder notNil ifTrue:[
-	topClassHolder removeDependent:self
+        topClassHolder removeDependent:self
     ].
-    topClassHolder := aTriggerValue.
+    topClassHolder := aValueHolder.
+
     topClassHolder notNil ifTrue:[
-	topClassHolder isBehavior ifTrue:[self halt:'should not happen'].
-	topClassHolder addDependent:self
+        topClassHolder isBehavior ifTrue:[self halt:'should not happen'].
+        topClassHolder addDependent:self.
+    ].
+
+    newTopClass := topClassHolder value.
+    newTopClass ~~ oldTopClass ifTrue:[
+        self enqueueDelayedUpdateList.
     ].
 ! !
 
@@ -275,7 +285,7 @@
 !HierarchicalClassList class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libtool/Tools_HierarchicalClassList.st,v 1.5 2006-03-28 15:27:27 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libtool/Tools_HierarchicalClassList.st,v 1.6 2006-03-28 17:45:33 cg Exp $'
 ! !
 
 HierarchicalClassList initialize!