unknown column gmap_taxonomy_node.marker in field list

Hi,
I am trying to use the taxonomy markers, but when I try to set the marker handling (within view editing) to "by term" I get following warning:

user warning: Unknown column 'gmap_taxonomy_node.marker' in 'field list' query: SELECT location.lid AS lid, node.title AS node_title, node.nid AS node_nid, node_revisions.body AS node_revisions_body, node_revisions.format AS node_revisions_format, location.latitude AS gmap_lat, location.longitude AS gmap_lon, gmap_taxonomy_node.marker AS gmap_node_marker FROM location location LEFT JOIN location_instance location_instance ON location.lid = location_instance.lid LEFT JOIN node node ON location_instance.vid = node.vid LEFT JOIN node_revisions node_revisions ON location_instance.vid = node_revisions.vid WHERE (node.status <> 0 OR (node.uid = 1 AND 1 <> 0) OR 1 = 1) AND (node.type in ('spot')) LIMIT 0, 10 in /mnt/data/accounts/k/kubistaj/data/www/drupal6/sites/default/modules/views/plugins/views_plugin_query_default.inc on line 1091.

any help?