--- a/graphics/GraphicCommons.py	Wed Feb 15 00:27:31 2012 +0100
+++ b/graphics/GraphicCommons.py	Wed Feb 15 00:29:02 2012 +0100
@@ -27,6 +27,7 @@
 from math import *
 from types import *
 import datetime
+from threading import Semaphore
 
 #-------------------------------------------------------------------------------
 #                               Common constants
@@ -304,6 +305,7 @@
         self.DataConsumers = {}
         
         self.LastRefreshTime = gettime()
+        self.RefreshLock = Semaphore()
         
         self.RefreshTimer = wx.Timer(self, -1)
         self.Bind(wx.EVT_TIMER, self.OnRefreshTimer, self.RefreshTimer)
@@ -327,9 +329,9 @@
         return self.Debug
     
     def Inhibit(self, inhibit):
-        self.Inhibited = inhibit
         for consumer, iec_path in self.DataConsumers.iteritems():
             consumer.Inhibit(inhibit)
+        self.Inhibited = inhibit
     
     def AddDataConsumer(self, iec_path, consumer):
         if self.DataProducer is None:
@@ -368,23 +370,24 @@
         self.RefreshNewData()
         event.Skip()
     
-    def NewDataAvailable(self):
+    def NewDataAvailable(self, *args, **kwargs):
         self.RefreshTimer.Stop()
         if not self.Inhibited:
             current_time = gettime()
-            if current_time - self.LastRefreshTime > REFRESH_PERIOD:
-                self.LastRefreshTime = current_time
+            if current_time - self.LastRefreshTime > REFRESH_PERIOD and self.RefreshLock.acquire(False):
+                self.LastRefreshTime = gettime()
                 self.Inhibit(True)
-                wx.CallAfter(self.RefreshViewOnNewData)
+                wx.CallAfter(self.RefreshViewOnNewData, *args, **kwargs)
             
-    def RefreshViewOnNewData(self):
+    def RefreshViewOnNewData(self, *args, **kwargs):
         if self:
-            self.RefreshNewData()
+            self.RefreshNewData(*args, **kwargs)
             self.RefreshTimer.Start(int(REFRESH_PERIOD * 1000), oneShot=True)
     
-    def RefreshNewData(self):
+    def RefreshNewData(self, *args, **kwargs):
         self.Inhibit(False)
-
+        self.RefreshLock.release()
+        
 #-------------------------------------------------------------------------------
 #                               Viewer Rubberband
 #-------------------------------------------------------------------------------