[MAV 001:1] PreArm: Compass not calibrated

[workino]

Hello
i have hk multiwii pro red

http://hobbyking.com/hobbyking/store/__26588__MultiWii_PRO_Flight_Controller_w_MTK_GPS_Module.html

but when i try to arm motor i got this error.

i made calibration 20 times now.
How can i solve this issue?