Index: wp-admin/includes/plugin.php
===================================================================
--- wp-admin/includes/plugin.php	(revision 17454)
+++ wp-admin/includes/plugin.php	(working copy)
@@ -583,7 +583,7 @@
 			$key = array_search( $plugin, $current );
 			if ( false !== $key ) {
 				$do_blog = true;
-				array_splice( $current, $key, 1 );
+				unset( $current[ $key ] );
 			}
 		}