--- a/UserPreferences.st	Fri Jun 12 08:54:01 2015 +0200
+++ b/UserPreferences.st	Wed Jun 17 09:39:41 2015 +0200
@@ -1,3 +1,5 @@
+"{ Encoding: utf8 }"
+
 "
  COPYRIGHT (c) 1998 by eXept Software AG
 	      All Rights Reserved
@@ -1789,8 +1791,8 @@
     "change the flag which enables a workaround for a redraw bug when running X/Linux in the VMWare virtual machine"
 
     self at:#enableVMWareDrawingBugWorkaround put:aBoolean.
-    Screen current platformName = 'X11' ifTrue:[
-	Screen current maxOperationsUntilFlush:(aBoolean ifTrue:[1] ifFalse:[nil])
+    (Screen notNil and:[Screen current notNil and:[Screen current platformName = #X11]]) ifTrue:[
+        Screen current maxOperationsUntilFlush:(aBoolean ifTrue:[1] ifFalse:[nil])
     ].
 
     "
@@ -5334,11 +5336,11 @@
 !UserPreferences class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libbasic/UserPreferences.st,v 1.405 2015-05-29 11:38:19 cg Exp $'
+    ^ '$Header$'
 !
 
 version_CVS
-    ^ '$Header: /cvs/stx/stx/libbasic/UserPreferences.st,v 1.405 2015-05-29 11:38:19 cg Exp $'
+    ^ '$Header$'
 !
 
 version_SVN