diff --git a/etgtools/extractors.py b/etgtools/extractors.py
index 9fd8473c..76a9393d 100644
--- a/etgtools/extractors.py
+++ b/etgtools/extractors.py
@@ -239,11 +239,7 @@ class FunctionDef(BaseDef):
         if element is not None:
             self.extract(element)
             
-            
-    def releaseGIL(self, release=True):
-        self.pyReleaseGIL = release
-
-        
+                    
     def extract(self, element):
         super(FunctionDef, self).extract(element)
         self.type = flattenNode(element.find('type'))
@@ -257,13 +253,23 @@ class FunctionDef(BaseDef):
             # briefDoc for this ParamDef object.
 
             
+    def releaseGIL(self, release=True):
+        self.pyReleaseGIL = release
+
+        
     def setCppCode(self, code):
+        """
+        Use the given C++ code instead of that automatically generated by the
+        back-end. This is similar to adding a new C++ method, except it uses
+        info we've alread received from the source XML such as the argument
+        types and names, docstring, etc.
+        """
         self.cppCode = code
         
             
     def checkForOverload(self, methods):
         for m in methods:
-            if isinstance(m, MethodDef) and m.name == self.name:
+            if isinstance(m, FunctionDef) and m.name == self.name:
                 m.overloads.append(self)
                 m.isOverloaded = self.isOverloaded = True
                 return True
diff --git a/etgtools/tweaker_tools.py b/etgtools/tweaker_tools.py
index 4f36bb2a..ec7953d5 100644
--- a/etgtools/tweaker_tools.py
+++ b/etgtools/tweaker_tools.py
@@ -32,7 +32,7 @@ def removeWxPrefixes(node):
                 item.pyName = item.name[2:]
                 item.wxDropped = True
         if item.name.startswith('wxEVT_'):
-            # give these theire actual name so the auto-renamer won't touch them
+            # give these their actual name so the auto-renamer won't touch them
             item.pyName = item.name
             
 
@@ -69,12 +69,13 @@ def fixEventClass(klass):
     Add the extra stuff that an event class needs that are lacking from the
     interface headers.
     """
+    assert isinstance(klass, extractors.ClassDef)
     if klass.name != 'wxEvent':
         # Clone() in wxEvent is pure virtual, so we need to let the back-end
         # know that the other event classes have an implementation for it so
         # it won't think that they are abstract classes too.
-        wig = extractors.WigCode("virtual wxEvent* Clone();")
-        klass.addItem(wig)
+        if not klass.findItem('Clone'):
+            klass.addPublic('virtual wxEvent* Clone() const /Factory/;')
 
     # Add a private assignment operator so the back-end (if it's watching out
     # for this) won't try to make copies by assignment.
@@ -107,7 +108,8 @@ def removeVirtuals(klass):
             
 def addWindowVirtuals(klass):
     """
-    
+    Either turn the virtual flag back on or add a delcaration for the subset of
+    the C++ virtuals in wxWindow classes that we will be supporting.
     """
     publicWindowVirtuals = [      
         ('GetClientAreaOrigin',      'wxPoint GetClientAreaOrigin() const'),