Copter orientation off by 45°?

Looking at this view in APM Planner, the red line is what the Planner thinks the front of my quadcopter is, but the copter’s in an ‘X’ config (the default, right?) where the “front” is between the front two booms. The copter’s behaving rather odd in stabilized mode, and I’m wondering if this is why. But I can’t figure out where the setting is that’ll tell the copter that its front is between the booms.

I should add this is a brand new 3DR APM quad with the latest planner and APM 3.0.1 firmware.

Oops, my bad. Figured it out. Hd the wrong configuration in the compass calibration screen…oh vey.