I noticed while loitering with my (recently installed) FPV stuff on that the APM was having a bit of a hard time staying in place in the presence of any wind.  A coulpe of times, to my consternation, the thing suddenly veered off like it was making an escape.  One time  I went back to Stabilize and got it under control, the other time (I was in a wide open field experimenting to see WTF was going on), I let it go and it stopped about 40 meters away from the loiter point, then slowly made its way back.

Randy did note that GPS glitches can cause agressive maneuvers.  Well, I'm here to verify that.  The HK 900 mHz video definitely glitched the GPS.  Once I disconnected the video system (leaving the telemetry on), the thing stayed in one spot like it was cemented there, wind be damned. Impressive.

So, lessons learned-- Beware GPS interference from 900mHz video, and yes, APM 30. will definitely cause you to pucker up when loitering if you have the video running.  It looks like the Ublox GPS doesn't really like the HK FPV system. 

And the 3.0 loiter is awesome.  Great job, devs!