WMM eats 0> priority packets

[RB Client (pseudo bridge enabled)] ==> [RB-AP]
after some time out client router start droping all packets,
which was market with set-priority greater 0, on the access point.

RB-AP:
-ROS: 3.30@RB532
-wireless-test package installed

RB-Client:
-ROS: 4.5@RB411