Index: modules/block.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/Attic/block.module,v
retrieving revision 1.206.2.7
diff -u -r1.206.2.7 block.module
--- modules/block.module	14 Nov 2006 10:46:07 -0000	1.206.2.7
+++ modules/block.module	19 Dec 2006 17:46:23 -0000
@@ -204,7 +204,7 @@
 
   // If non-default theme configuration has been selected, set the custom theme.
   if (arg(3)) {
-    $custom_theme = arg(3);
+    $theme_key = arg(3);
   }
   else {
     $custom_theme = variable_get('theme_default', 'bluemarine');