--- a/Workspace.st	Thu Feb 05 00:14:56 2015 +0100
+++ b/Workspace.st	Fri Feb 06 14:50:52 2015 +0100
@@ -11,6 +11,8 @@
 "
 "{ Package: 'stx:libwidg' }"
 
+"{ NameSpace: Smalltalk }"
+
 TextCollector subclass:#Workspace
 	instanceVariableNames:'doItAction codeStartPosition errorFgColor errorBgColor
 		commentStrings autoDefineWorkspaceVariables simulatedSelf
@@ -327,7 +329,6 @@
     DefaultViewBackground := StyleSheet colorAt:'codeView.backgroundColor'.
 ! !
 
-
 !Workspace class methodsFor:'getting a new Workspace'!
 
 open
@@ -1843,7 +1844,7 @@
                                 browserClass browseReferendsOf:nsClass name
                             ] ifFalse:[
                                 "/ an instvar?
-                                (cls allInstVarNames includes:nameOfVariable) ifTrue:[
+                                (cls notNil and:[cls allInstVarNames includes:nameOfVariable]) ifTrue:[
                                     browserClass 
                                         browseInstRefsTo:nameOfVariable 
                                         under:(cls whichClassDefinesInstVar:nameOfVariable) 
@@ -2347,10 +2348,10 @@
 !Workspace class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libwidg/Workspace.st,v 1.339 2014-11-15 15:10:59 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libwidg/Workspace.st,v 1.340 2015-02-06 13:50:52 cg Exp $'
 !
 
 version_CVS
-    ^ '$Header: /cvs/stx/stx/libwidg/Workspace.st,v 1.339 2014-11-15 15:10:59 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libwidg/Workspace.st,v 1.340 2015-02-06 13:50:52 cg Exp $'
 ! !