diff -r 4f4369e63f5e -r 6abd6e3599f4 web/form.py
--- a/web/form.py	Mon Apr 12 14:41:01 2010 +0200
+++ b/web/form.py	Tue Apr 13 12:19:24 2010 +0200
@@ -191,7 +191,7 @@
             warn('[3.6.1] restore_previous_post already called, remove this call',
                  DeprecationWarning, stacklevel=2)
             return
-        forminfo = self._cw.get_session_data(sessionkey, pop=True)
+        forminfo = self._cw.session.data.pop(sessionkey, None)
         if forminfo:
             self._form_previous_values = forminfo['values']
             self._form_valerror = forminfo['error']