Problems with ir-lock and pixhawk 3.3.3

hi i have problem to use ir-lock and pixhaws with firmware 3.3.3 .
i have follow all instrunctions in ir-lock website.
in my log file heal is 1 but px = 0 py = 0 vx = 0 vy = 0 always during Precision Landing.

Where is the problem?
i use Tower to pilot my copter.

please help me.

Please update to arducopter 3.5.4-rc1

i will try and i will post my log file.