The latest versions in the MOODLE_35_STABLE and MOODLE_34_STABLE branches have fix for this. You can get them from Github.
https://github.com/PoetOS/moodle-mod_questionnaire/tree/MOODLE_35_STABLE
https://github.com/PoetOS/moodle-mod_questionnaire/tree/MOODLE_34_STABLE