Exposed filters: not working with force single

I have following combination:
- Drupal 5.2
- Views 1.6
- CCK Taxonomy 1.2

When I create an exposed filter based on a CCK Taxonomy field, the filter is working until I use 'Force single'. Then the views returns all nodes, whatever selection I make in the filter. When I disable 'Force single' the exposed filter is working perfect. The options 'Optional' and 'Lock operator' are working fine.