I changed the user permissions but the user still can view some pages he should not. What's wrong?

General Questions
User's permissions in a project always override user's permissions in a portfolio and in a role. To view or change user's permissions in a specific project:
  1. Open Project Details page,
  2. Click on the user name in the "Project members" section,
  3. Click on the "Edit project member role and permissions" item in the contextual menu,
  4. Set the required permissions and click on the "Update" button,
  5. Save the project by clicking on the "Save and close" button.

  6. If you want to change a user's role in the project use the same steps as above and choose a required role in the "Role for project member" drop-down list then click on the "Change role" button before the step 4 (clicking on the "Update" button).