Index: CronTrigger.java
===================================================================
--- CronTrigger.java	(revision 811)
+++ CronTrigger.java	(working copy)
@@ -862,22 +862,33 @@
     public void updateWithNewCalendar(org.quartz.Calendar calendar, long misfireThreshold)
     {
         nextFireTime = getFireTimeAfter(previousFireTime);
+
+        if (nextFireTime == null || calendar == null) {
+            return;
+        }
         
         Date now = new Date();
-        do {
-            while (nextFireTime != null && calendar != null
-                    && !calendar.isTimeIncluded(nextFireTime.getTime())) {
-                nextFireTime = getFireTimeAfter(nextFireTime);
+        while (nextFireTime != null && !calendar.isTimeIncluded(nextFireTime.getTime())) {
+
+            nextFireTime = getFireTimeAfter(nextFireTime);
+
+            if(nextFireTime == null)
+            	break;
+            
+            //avoid infinite loop
+            java.util.Calendar c = java.util.Calendar.getInstance();
+            c.setTime(nextFireTime);
+            if (c.get(java.util.Calendar.YEAR) > YEAR_TO_GIVEUP_SCHEDULING_AT) {
+                nextFireTime = null;
             }
-            
+
             if(nextFireTime != null && nextFireTime.before(now)) {
                 long diff = now.getTime() - nextFireTime.getTime();
                 if(diff >= misfireThreshold) {
                     nextFireTime = getFireTimeAfter(nextFireTime);
-                    continue;
                 }
             }
-        }while(false);
+        }
     }
 
     /**