--- cron.php.orig	2006-06-27 12:54:55.625000000 +0700
+++ cron.php	2006-06-27 14:28:32.484375000 +0700
@@ -6,6 +6,12 @@
  * Handles incoming requests to fire off regularly-scheduled tasks (cron jobs).
  */
 
+/**
+ * Modified to prevent cron.php being run while previous run of tasks invoked by
+ * cron.php are still running
+ * AD Marshall <admarshall@gmail.com>, v.1.28.01, 2006/06/27 14:28 GMT+7
+ */
+ 
 include_once 'includes/bootstrap.inc';
 include_once 'includes/common.inc' ;
 
@@ -13,20 +19,20 @@
 if (!ini_get('safe_mode')) {
   set_time_limit(240);
 }
-
 // Check if the last cron run completed
 if (variable_get('cron_busy', false)) {
-  watchdog('cron', t('Last cron run did not complete.'), WATCHDOG_WARNING);
+
+  watchdog('cron', t('Cron Running: Ignored attempted ReRun.'), WATCHDOG_WARNING);
 }
 else {
   variable_set('cron_busy', true);
-}
 
 // Iterate through the modules calling their cron handlers (if any):
-module_invoke_all('cron');
+  module_invoke_all('cron');
 
 // Clean up
-variable_set('cron_busy', false);
-watchdog('cron', t('Cron run completed'));
+  variable_set('cron_busy', false);
+  watchdog('cron', t('Cron run completed'));
+}
 
 ?>