--- a/ImageView.st	Mon Jan 16 17:18:55 2017 +0100
+++ b/ImageView.st	Mon Jan 16 17:22:06 2017 +0100
@@ -687,8 +687,11 @@
     oldMagnifiedImage := magnifiedImage.
     magnifiedImage := nil.
     self generateMagnifiedImage.
-    oldMagnifiedImage extent = magnifiedImage extent ifFalse:[
-        self clear.
+    (oldMagnifiedImage isNil
+      or:[ magnifiedImage isNil
+      or:[ oldMagnifiedImage extent ~= magnifiedImage extent ]]
+    ) ifTrue:[
+        "/ self clear.
         self invalidate.
     ].
 ! !