Analytics Software

I`ve read Venkat`s blog http://oraclebizint.wordpress.com/2007/08/29/obi-ee-10133-and-vpd/

I have an working policy on my table:

personal_history(district_id,city_id,company_id,department_id,job_id,employee_id, salary)

For example on my policy the chiefs of department see only information on his employees, the managers for their own department.

My policy function is far more complicated than Venkat`s Executive_Apply. I`ve checked VPD in database connection.My shared connection is based on vpd_admin which i gave him dba role.
I put "select set_context_function(':USER') from dual" on before query in OBIEE Connection script, still in Answers there is no difference between managers and chiefs of department in number of rows.

Why? What i`ve done wrong?

Thank you!
Razvan.