--- a/WindowSensor.st	Mon Mar 13 17:40:36 2017 +0100
+++ b/WindowSensor.st	Mon Apr 03 12:14:18 2017 +0200
@@ -1977,7 +1977,7 @@
                         (wgProcess := evView windowGroup process) notNil ifTrue:[
                             wgProcess isDebugged ifTrue:[
                                 "/ but not for debuggers inside debuggers
-                                (evView topView isDebugView) ifFalse:[
+                                (evView topView isKindOf:DebugView) ifFalse:[
                                     DebugView allInstances do:[:dbg |
                                         dbg inspectedProcess == wgProcess ifTrue:[
                                             dbg window topView raiseDeiconified
@@ -2695,6 +2695,8 @@
      Called privately when pointer enters a view."
 
     |state|
+	
+	aDevice isNil ifTrue:[^ self].
 
     "/ Prevents wrong behavior in the following scenario:
     "/    ctrl is pressed in a view