--- a/DebugView.st	Wed Feb 11 17:08:18 2009 +0100
+++ b/DebugView.st	Wed Feb 11 17:37:35 2009 +0100
@@ -167,13 +167,15 @@
         OpenDebuggers notNil ifTrue:[
             active := Processor activeProcess.
             OpenDebuggers do:[:aDebugger |
-                (aDebugger inspectedProcess == active) ifTrue:[
-                    aDebugger device isOpen ifTrue:[
-                        "/ 'entering stepping debugger again' printNL.
-                        aDebugger unstep.
-                        aDebugger setLabelFor:aString in:active.
-                        aDebugger mayProceed:mayProceed.
-                        ^ aDebugger enter:aContext select:nil.
+                (aDebugger notNil and:[aDebugger ~~ 0]) ifTrue:[
+                    (aDebugger inspectedProcess == active) ifTrue:[
+                        aDebugger device isOpen ifTrue:[
+                            "/ 'entering stepping debugger again' printNL.
+                            aDebugger unstep.
+                            aDebugger setLabelFor:aString in:active.
+                            aDebugger mayProceed:mayProceed.
+                            ^ aDebugger enter:aContext select:nil.
+                        ]
                     ]
                 ]
             ]
@@ -6539,7 +6541,7 @@
 !DebugView class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libtool/DebugView.st,v 1.460 2009-02-02 16:43:19 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libtool/DebugView.st,v 1.461 2009-02-11 16:37:35 cg Exp $'
 ! !
 
 DebugView initialize!