Index: class-wp-users-list-table.php
===================================================================
--- class-wp-users-list-table.php	(revision 23389)
+++ class-wp-users-list-table.php	(working copy)
@@ -312,8 +312,9 @@
 					$r .= "</td>";
 					break;
 				default:
+					$value = property_exists( $user_object, $column_name ) ? $user_object->$column_name : '';
 					$r .= "<td $attributes>";
-					$r .= apply_filters( 'manage_users_custom_column', '', $column_name, $user_object->ID );
+					$r .= apply_filters( 'manage_users_custom_column', $value, $column_name, $user_object->ID );
 					$r .= "</td>";
 			}
 		}