diff -Nur asterisk-1.6.2.7-rc1-old/include/asterisk/heap.h asterisk-1.6.2.7-rc1-new/include/asterisk/heap.h
--- asterisk-1.6.2.7-rc1-old/include/asterisk/heap.h	2010-04-20 00:00:00.000000000 +0800
+++ asterisk-1.6.2.7-rc1-new/include/asterisk/heap.h	2010-04-20 00:00:00.000000000 +0800
@@ -272,6 +272,8 @@
  *       heap and verifies that every node is properly placed relative to its children.
  * \since 1.6.1
  */
-int ast_heap_verify(struct ast_heap *h);
+unsigned int ast_heap_verify(struct ast_heap *h);
+
+void ast_heap_build(struct ast_heap *h);
 
 #endif /* __AST_HEAP_H__ */
diff -Nur asterisk-1.6.2.7-rc1-old/main/heap.c asterisk-1.6.2.7-rc1-new/main/heap.c
--- asterisk-1.6.2.7-rc1-old/main/heap.c	2010-04-20 00:00:00.000000000 +0800
+++ asterisk-1.6.2.7-rc1-new/main/heap.c	2010-04-20 00:00:00.000000000 +0800
@@ -83,7 +83,7 @@
 	}
 }
 
-int ast_heap_verify(struct ast_heap *h)
+unsigned int ast_heap_verify(struct ast_heap *h)
 {
 	unsigned int i;
 
@@ -93,13 +93,13 @@
 
 		if (l <= h->cur_len) {
 			if (h->cmp_fn(heap_get(h, i), heap_get(h, l)) <= 0) {
-				return -1;
+				return i;
 			}
 		}
 
 		if (r <= h->cur_len) {
 			if (h->cmp_fn(heap_get(h, i), heap_get(h, r)) <= 0) {
-				return -1;
+				return i;
 			}
 		}
 	}
@@ -229,6 +229,14 @@
 	}
 }
 
+void ast_heap_build(struct ast_heap *h)
+{
+	unsigned int i;
+
+	for (i = (h->cur_len / 2); i >= 1; i--)
+		max_heapify(h, i);
+}
+
 #ifdef MALLOC_DEBUG
 int _ast_heap_push(struct ast_heap *h, void *elm, const char *file, int lineno, const char *func)
 #else
diff -Nur asterisk-1.6.2.7-rc1-old/main/sched.c asterisk-1.6.2.7-rc1-new/main/sched.c
--- asterisk-1.6.2.7-rc1-old/main/sched.c	2010-04-20 00:00:00.000000000 +0800
+++ asterisk-1.6.2.7-rc1-new/main/sched.c	2010-04-20 00:00:00.000000000 +0800
@@ -581,7 +581,8 @@
 int ast_sched_runq(struct sched_context *con)
 {
 	struct sched *current;
-	struct timeval when;
+	struct timeval when = ast_tvnow();
+	unsigned int i;
 	int numevents;
 	int res;
 
@@ -589,6 +590,21 @@
 		
 	ast_mutex_lock(&con->lock);
 
+	if ((i = ast_heap_verify(con->sched_heap)) != 0) {
+/*#ifdef DEBUG_SCHEDULER*/
+		struct timeval delta;
+		current = ast_heap_peek(con->sched_heap, i);
+		delta = ast_tvsub(current->when, when);
+		ast_debug(1, "ID %d (%p, %p, %ld : %ld) violates heap property!\n",
+			current->id,
+			current->callback,
+			current->data,
+			(long)delta.tv_sec,
+			(long int)delta.tv_usec);
+/*#endif*/
+		ast_heap_build(con->sched_heap);
+	}
+
 	for (numevents = 0; (current = ast_heap_peek(con->sched_heap, 1)); numevents++) {
 		/* schedule all events which are going to expire within 1ms.
 		 * We only care about millisecond accuracy anyway, so this will