Hi Marcio -
1.9 has been an unsupported version of Moodle since June 2012. The current version of Moodle is 3.1, and 3.2 is just around the corner. For 1.9, even 1.9.4 is old and likely insecure. You should really plan to upgrade as soon as you can.
From what I recall, the module worked with groups then. You may need to check that the course is using groups, and that the questionnaire instance is likewise using group.
mike