diff --git a/pandora_agents/win32/ChangeLog b/pandora_agents/win32/ChangeLog
index 945daf3636..79bcdea210 100644
--- a/pandora_agents/win32/ChangeLog
+++ b/pandora_agents/win32/ChangeLog
@@ -1,3 +1,10 @@
+2013-04-04  Koichiro KIKUCHI <koichiro@rworks.jp>
+
+	* windows_service.cc,
+	  pandora_windows_service.cc,
+	  windows_service.h: Set iteration base ticks after sleeping startup_delay
+	 to exclude time taken by startup_delay from sleep time subtraction.
+
 2013-04-03  Koichiro KIKUCHI <koichiro@rworks.jp>
 
 	* windows_service.cc: Fixed typo of my previous commit.
diff --git a/pandora_agents/win32/pandora_windows_service.cc b/pandora_agents/win32/pandora_windows_service.cc
index e2b1813305..239b0fc7cc 100644
--- a/pandora_agents/win32/pandora_windows_service.cc
+++ b/pandora_agents/win32/pandora_windows_service.cc
@@ -1629,8 +1629,6 @@ void
 Pandora_Windows_Service::pandora_run_broker (string config) {
 	Pandora_Agent_Conf  *conf = NULL;
 	string server_addr;
-    int startup_delay = 0;
-    static unsigned char delayed = 0;
 	unsigned char data_flag = 0;
 	unsigned char intensive_match;
 	
@@ -1725,7 +1723,7 @@ Pandora_Windows_Service::pandora_run () {
 	string server_addr, conf_file, *all_conf;
 	int startup_delay = 0;
 	int i, num;
-	static unsigned char delayed = 0;
+	static bool startup = true;
 	unsigned char data_flag = 0;
 	unsigned char intensive_match;
 	
@@ -1733,13 +1731,17 @@ Pandora_Windows_Service::pandora_run () {
 	
 	conf = this->getConf ();
 	
+	/* process only once at startup */
+	if (startup) {
+		startup = false;
  	/* Sleep if a startup delay was specified */
  	startup_delay = atoi (conf->getValue ("startup_delay").c_str ()) * 1000;
-	if (startup_delay > 0 && delayed == 0) {
-		delayed = 1;
+		if (startup_delay > 0) {
 		pandoraLog ("Delaying startup %d miliseconds", startup_delay);
 		Sleep (startup_delay);
 	}
+		setIterationBaseTicks(GetTickCount());
+	}
 
 	/* Set the run time */
 	this->run_time = time (NULL);
diff --git a/pandora_agents/win32/windows_service.cc b/pandora_agents/win32/windows_service.cc
index 7fad95033b..a7f500f0f1 100644
--- a/pandora_agents/win32/windows_service.cc
+++ b/pandora_agents/win32/windows_service.cc
@@ -112,10 +112,11 @@ Windows_Service::setInitFunction (void (Windows_Service::*f) ()) {
 void
 Windows_Service::execRunFunction () {
 	int sleep_time_remain;
-	DWORD tickbase, ticknow;
+	DWORD ticknow;
 
 	if (run_function != NULL) {
-		tickbase = GetTickCount();
+		// init here
+		setIterationBaseTicks(GetTickCount());
 
 		do {
 			(this->*run_function) ();
@@ -127,14 +128,14 @@ Windows_Service::execRunFunction () {
 
 			// Subtract time taken by run_funtion() from sleep_time
 			// to *start* each iteration with the same interval
-			sleep_time_remain = sleep_time - (ticknow - tickbase);
+			sleep_time_remain = sleep_time - (ticknow - iter_base_ticks);
 
 			if (0 <= sleep_time_remain && sleep_time_remain <= sleep_time) {
-				tickbase += sleep_time;
+				setIterationBaseTicks(iter_base_ticks + sleep_time);
 			} else {
 				// run_function() took more than "sleep_time", or something goes wrong.
 				sleep_time_remain = 0; // don't sleep
-				tickbase = ticknow; // use current ticks as base ticks
+				setIterationBaseTicks(ticknow); // use current ticks as base ticks
 			}
 		} while (WaitForSingleObject (stop_event, sleep_time_remain) != WAIT_OBJECT_0);
 	}
@@ -175,6 +176,19 @@ Windows_Service::setSleepTime (unsigned int s) {
 	current_service->sleep_time = sleep_time;
 }
 
+/** 
+ * Set the base tick count.
+ *
+ * This ticks used to start each iteration with the same
+ * interval (this->sleep_time)
+ * @param ticks base tick count..
+ */
+void
+Windows_Service::setIterationBaseTicks(DWORD ticks) {
+	iter_base_ticks = ticks;
+	current_service->iter_base_ticks = ticks;
+}
+
 /** 
  * Install the service in the Windows services system.
  * 
diff --git a/pandora_agents/win32/windows_service.h b/pandora_agents/win32/windows_service.h
index 38c1a77a7b..f918017b53 100644
--- a/pandora_agents/win32/windows_service.h
+++ b/pandora_agents/win32/windows_service.h
@@ -42,6 +42,7 @@ protected:
 private:
 	HANDLE    stop_event;
 	int       sleep_time;
+	DWORD     iter_base_ticks;
 	SC_HANDLE sc_service;
 	
 	void (Windows_Service::*run_function)  ();
@@ -62,6 +63,7 @@ public:
 	void  setInitFunction  (void (Windows_Service::*f) ());
 	LPSTR getServiceName   ();
 	void  setSleepTime     (unsigned int s);
+	void  setIterationBaseTicks(DWORD ticks);
 
 	void  execRunFunction  ();
 	void  execInitFunction ();