diff --git a/src/backend/pyloader/ScriptAdapter.py b/src/backend/pyloader/ScriptAdapter.py
index d6a66d5..2100da7 100644
--- a/src/backend/pyloader/ScriptAdapter.py
+++ b/src/backend/pyloader/ScriptAdapter.py
@@ -79,7 +79,7 @@ class ScriptAdapter :
     #
     # @param self The caller object
     def async_is_preemptive(self):
-        _g_mutex.lock(ScriptAdapter._wrap_is_preemptive, self)
+        self._g_mutex.lock(ScriptAdapter._wrap_is_preemptive, self)
 
     def _wrap_is_preemptive(self):
         thread.start_new_thread(ScriptAdapter._wrap_is_preemptive_callback, (self,))
@@ -105,5 +105,5 @@ class ScriptAdapter :
     def get_return_value(self):
         return self._ret_val
 
-    def test_lock(self):
+    def mutex_test_lock(self):
         return self._g_mutex.test()
diff --git a/src/backend/pyloader/python_policy.cc b/src/backend/pyloader/python_policy.cc
index 4d412d4..2697413 100644
--- a/src/backend/pyloader/python_policy.cc
+++ b/src/backend/pyloader/python_policy.cc
@@ -131,6 +131,7 @@ PythonPolicy::is_pre_emptive() const throw(UserInterruptException)
   
   // Parse return value stored in global Python object
   retval = PyObject_CallMethod(_adapter, "get_return_value", NULL);
+  assert(retval);
   bool ret = PyObject_IsTrue(retval);
   Py_DECREF(retval);
   return ret;
@@ -146,6 +147,7 @@ PythonPolicy::get_time_slice() const throw(UserInterruptException) {
   
   // Parse return value stored in global Python object
   retval = PyObject_CallMethod(_adapter, "get_return_value", NULL);
+  assert(retval);
   long tmp = PyInt_AsLong(retval);
   Py_DECREF(retval);
 
@@ -167,7 +169,7 @@ PythonPolicy::wait_unlock() const throw(UserInterruptException)
       usleep(WAIT_FOR); // hack'a'ton! magggggiccc nummmbeeerrrrrs!!
       Py_BLOCK_THREADS;
       
-      PyObject* retval = PyObject_CallMethod(_adapter, "test_lock", NULL);
+      PyObject* retval = PyObject_CallMethod(_adapter, "mutex_test_lock", NULL);
       assert(retval);
       still_locked = PyObject_IsTrue(retval);
       Py_DECREF(retval);