I checked to see the Reset on Moodle 1.9.5+ (Build: 20090629) is working, and it seems to be OK (see attached screenshot).
Please check to see if the following functions are available in your "mod/hotpot/lib.php" file on yoru Moodle site:
- hotpot_reset_userdata()
- hotpot_reset_course_form_definition()
- hotpot_reset_course_form_defaults()
Gordon