I have tried Mission Planner 1.1.27 and 1.1.31 and am getting similar results. I am using Xplane 10 and APM v1.
The link seems fine, data is populated in the simulation screen, I can fly the plane, I think stabilize is trying to work (it has Ardupilot Output numbers that change, the PID is just way off) but the "Flight Data" and "Flight Planner" tabs do nothing.
So when I try to set my current location with the Home Location button, it says "...commect to your APM and wait for GPS lock." and the Flight Data screen looks just like it does when nothing is connected.
Any ideas what is going on here?