Index: datagrid/grids.py
===================================================================
--- datagrid/grids.py	(revision 11689)
+++ datagrid/grids.py	(working copy)
@@ -9,7 +9,6 @@
 from django.utils.translation import ugettext as _
 from django.views.decorators.cache import cache_control
 
-
 class Column(object):
     """
     A column in a data grid.
@@ -359,7 +358,6 @@
 
         expand_columns = []
         normal_columns = []
-        self.db_field_map = {}
 
         for colname in colnames:
             try: