Filter date (Date>=now) does not work ?

I have a view in which I show activities where I have set a filter on field_date. However, the filter does not work 100%. According to the code below it adds an "OR" SQL statement in the "WHERE" clause checking out the 'node.changed' value. I I leave this code out my view works as expected.

I just wonder why the View module adds this line to my SQL statement. Any suggestions?

Regards,

Nyborg

SELECT node_data_field_date.field_date_value AS node_data_field_date_field_date_value, 
node_data_field_date.field_date_value2 AS node_data_field_date_field_date_value2, 
node.type AS node_type, 
node.nid AS nid, 
node.vid AS node_vid, 
node.title AS node_title, 
node.language AS node_language 
FROM node node  
LEFT JOIN content_type_event node_data_field_date ON node.vid = node_data_field_date.vid 
WHERE ((node.type in ('event')) 
  AND (node.status = 1)) 
  AND (
    (DATE_FORMAT(STR_TO_DATE(node_data_field_date.field_date_value2, '%Y-%m-%dT%T'), '%Y-%m-%d') >= '2011-09-21') 
    OR (
    (DATE_FORMAT(FROM_UNIXTIME(node.changed), '%Y-%m') <= '2011-09' AND DATE_FORMAT(FROM_UNIXTIME(node.changed), '%Y-%m') >= '2011-09'))) 
ORDER BY node_data_field_date_field_date_value ASC, node_data_field_date_field_date_value2 ASC