Index: /trunk/ippMonitor/czartool/czartool/CzarDb.pm
===================================================================
--- /trunk/ippMonitor/czartool/czartool/CzarDb.pm	(revision 32796)
+++ /trunk/ippMonitor/czartool/czartool/CzarDb.pm	(revision 32797)
@@ -718,4 +718,6 @@
             # times
             $timeSep = $self->diffTimesInSecs($thisTimestamp, $lastTimestamp);
+            if ($timeSep == 0) {$timeSep = 1;}; # HACK to prevent divide-by-zero
+
             $middleTime = $self->getMiddleTime($lastTimestamp, $thisTimestamp);
             $formattedMiddleTimestamp = $self->getFormattedDate($middleTime);
@@ -727,5 +729,5 @@
             # added, and store value to subtract from linear value below. If > 1000
             # processed per hour, then it must be wrong
-            if (($thisProcessed - $lastProcessed)/(($timeSep/3600)+1) > 1000) {
+            if (($thisProcessed - $lastProcessed)/($timeSep/3600) > 1000) {
                 $positiveJump = $thisProcessed - $lastProcessed;
             }
@@ -747,7 +749,7 @@
 
             # calculate first derivative in units of images per hour
-            $derivPending = $diffPending/($timeSep/3600 +1); 
-            $derivFaults = $diffFaults/($timeSep/3600 +1); 
-            $derivProcessed = $diffProcessed/($timeSep/3600 +1); 
+            $derivPending = $diffPending/($timeSep/3600); 
+            $derivFaults = $diffFaults/($timeSep/3600); 
+            $derivProcessed = $diffProcessed/($timeSep/3600); 
 
         }