diff -Naur nagios-HEAD.orig/base/events.c nagios-HEAD/base/events.c
--- nagios-HEAD.orig/base/events.c	2009-06-16 23:23:38.000000000 -0400
+++ nagios-HEAD/base/events.c	2009-10-20 21:26:03.000000000 -0400
@@ -996,7 +996,9 @@
 			/* remove the first event from the timing loop */
 			temp_event=event_list_high;
 			event_list_high=event_list_high->next;
-			event_list_high->prev=NULL;
+			/* we may have just removed the only item from the list */
+			if (event_list_high!=NULL)
+				event_list_high->prev=NULL;
 
 			/* handle the event */
 			handle_timed_event(temp_event);
