=== modified file 'glipper/History.py'
--- glipper/History.py	2011-11-29 10:10:58 +0000
+++ glipper/History.py	2011-12-14 16:55:48 +0000
@@ -65,7 +65,7 @@
 				self.history = self.history[0:self.max_elements]
 			
 			ctrl_c_item = get_glipper_clipboards().get_default_clipboard_text()
-			if ctrl_c_item not in self.history:
+			if ctrl_c_item is not None and ctrl_c_item not in self.history:
 				self.history[-1] = ctrl_c_item
 		
 		# if item is None, emit changed anyway because