Optical flow on APM 2.6 running ArduCopter V3.2.1

http://copter.ardupilot.com/wiki/common-optional-hardware/common-optical-flow-sensors-landingpage/common-mouse-based-optical-flow-sensor-adns3080/#connecting_the_sensor_to_the_apm25 -> this page says that “Note: as of 15-Sep-2012, the code to support the optical flow on the APM2.5 has not yet been released.” Is this still true or is the page out of date?

I’ve got the sensor plugged in and I ran the tests with python and the test hex file at the bottom the page and confirmed that the sensor was producing readings (sent the “m” command and got reasonable numbers back). However, when I go into Mission Planner (1.3.28) and re-flash the APM board to the ArduCopter firmware V3.2.1 (latest available for APM 2.6 AFAIK), enable optical flow on the “Initial Setup” page, and look at the opt_m_x, opt_m_y, opt_x, opt_y, and opt_qua vales on the the “Status” tab of the “Flight Data” page, they are all zero. Am I doing something wrong or is optical flow just not part of the 3.2.1 firmware?

Any help would be appreciated, thanks.