Index: django/contrib/admin/views/main.py
===================================================================
--- django/contrib/admin/views/main.py	(revision 1271)
+++ django/contrib/admin/views/main.py	(working copy)
@@ -361,7 +361,7 @@
                     try:
                         header = func.short_description
                     except AttributeError:
-                        header = func.__name__
+                        header = func.__name__.replace('_', ' ')
                 # Non-field list_display values don't get ordering capability.
                 raw_template.append('<th>%s</th>' % capfirst(header))
             else: