--- thunar-list-model-orig.c	2011-01-29 17:31:24.000000000 +0100
+++ thunar-list-model.c	2011-01-29 17:30:41.000000000 +0100
@@ -1643,11 +1643,19 @@
       description_b = g_content_type_get_description (content_type_b);
     }
 
-  if (!case_sensitive)
-    result = strcasecmp (description_a, description_b);
-  else
+  if (!case_sensitive) {
+    if(!description_a && !description_b)
+        result = strcasecmp ("a", "b");
+    else 
+        result = strcasecmp (description_a, description_b);
+  }
+  else {
+    if(!description_a && !description_b)
+        result = strcasecmp ("a", "b");
+    else {
     result = strcmp (description_a, description_b);
-
+    }
+  }
   g_free (description_a);
   g_free (description_b);