Filtering indirect date field: is it possible?

I am working on the department Web site. I have content type 'Semester' that has a CCK field field_date_start of type 'Date'. Another content type is 'Section' has a CCK field field_semester of type 'Node reference' that can reference content of type 'Semester'. I build a view that displays sections by semesters. I want to filter out sections where the start date is later than now.

I add 'Semester' as a Relationship. I can display '(Semester) Content: Start date' and can correctly sort by this field. However, when I try to filter by it, the field field_date_start is not displayed in the Content group. If I go to group 'Date', I can see 'Date: Date' field ("Filter any Views date field"). Under that umbrella, there is 'Content: Start date (field_date_start)', which I would assume enables me to do filtering. Unfortunately, it does not. At the moment I add this filter, I have no output anymore, regardless of the filtering operator (even 'is empty' or 'is not empty' do not work). Adding or removing the 'Semester' relationship for the filter does not change anything. What am I doing wrong? Any suggestions? Thanks!

I use Drupal 6.10, Views 6.x-2.x-dev, Date 6.x-2.x-dev.