Index: trac/Milestone.py
===================================================================
--- trac/Milestone.py	(revision 940)
+++ trac/Milestone.py	(working copy)
@@ -247,7 +247,10 @@
 
         action = self.args.get('action', 'view')
         id = self.args.get('id', -1)
-
+        # default of -1 on dictionary get() is not working for some reason
+        if len(id) == 0:
+            id = -1;
+            
         if action == 'new':
             self.perm.assert_permission(perm.MILESTONE_CREATE)
             self.render_editor(-1)