Merged revisions 72135 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

........
  r72135 | benjamin.peterson | 2009-04-29 19:23:11 -0500 (Wed, 29 Apr 2009) | 1 line

  prevent ref cycles by removing bound method on close()
........

Lib/aifc.py

@@ -690,6 +690,8 @@ class Aifc_write:
               self._datalength != self._datawritten or \
               self._marklength:
             self._patchheader()
+        # Prevent ref cycles
+        self._convert = None
         self._file.flush()
         self._file = None