--- a/display.rc	Tue Jul 16 11:49:58 2013 +0200
+++ b/display.rc	Wed Aug 14 20:22:33 2013 +0200
@@ -228,6 +228,7 @@
 
 display isNil ifTrue:[
     'display.rc [warning]: cannot determine display I am running on' errorPrintCR.
+    ^ self.
 ] ifFalse:[
     "
      if there is a corresponding file d_<displayName>.rc ...
@@ -442,7 +443,7 @@
 |currentScreen|
 
 currentScreen := Screen current.
-currentScreen == Screen default ifTrue:[
+(currentScreen notNil and:[ currentScreen == Screen default]) ifTrue:[
     |depthChange colorChange greyChange reconfigure|
 
     depthChange := false.