--- a/AbstractFileBrowser.st	Thu Aug 21 23:15:12 2008 +0200
+++ b/AbstractFileBrowser.st	Tue Aug 26 23:35:29 2008 +0200
@@ -6844,7 +6844,9 @@
 
 parentDirectoriesOfCurrentFiles
 
-    ^ (self currentSelectedObjects collect:[:file | file directory]) asSet
+    ^ (self currentSelectedObjects 
+        select:[:file | file notNil]
+        thenCollect:[:file | file directory]) asSet
 
     "Modified: / 04-12-2006 / 13:15:21 / cg"
 !
@@ -7405,5 +7407,5 @@
 !AbstractFileBrowser class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libtool/AbstractFileBrowser.st,v 1.375 2008-06-09 12:12:01 stefan Exp $'
+    ^ '$Header: /cvs/stx/stx/libtool/AbstractFileBrowser.st,v 1.376 2008-08-26 21:35:29 cg Exp $'
 ! !