Unknown column

Hi,
I'm updated to Views 6.x-2.12, Date 6.x-2.7 and Calendar 6.x-2.4
but now on /date-browser I'm getting the following error:

Unknown column 'node_data_field_datum.field_datum_value' in 'where clause' query: SELECT DISTINCT node.nid AS nid, node.type AS node_type FROM node node INNER JOIN node_access na ON na.nid = node.nid WHERE (na.grant_view >= 1 AND ((na.gid = 0 AND na.realm = 'all') OR (na.gid = 0 AND na.realm = 'content_access_author') OR (na.gid = 1 AND na.realm = 'content_access_rid') OR (na.gid = 0 AND na.realm = 'resume_owner'))) AND ( (DATE_FORMAT(STR_TO_DATE(node_data_field_datum.field_datum_value, '%Y-%m-%dT%T'), '%Y-%m') <= '2011-05' AND DATE_FORMAT(STR_TO_DATE(node_data_field_datum.field_datum_value2, '%Y-%m-%dT%T'), '%Y-%m') >= '2011-05') ) in modules/views/includes/view.inc in Zeile 775.

I'm a little bit confused, whats wrong and what I should do.
Please help.

Best regards.