In the Woodhome Walls encounter, there are a pair of victory squares directly behind the PC heroes. On the first turn I drop my wizard Baraz back to hold the squares while my warrior Î and my priest Fluttershy stand in their original starting positions to slow down the skeletons. Turns out they really weren't in much of a hurry and for the first two turns they just stood there. The screen shot is on the third turn when they finally decided to move. Edit: And they didn't move from that point forward.
I found them very aggressive when I played that encounter (earlier this week). Might have been an off glitch, or something in the ai's been moved around lately.
They were rushing like a mad skeletons last night so it could have been some bug you've encountered, interesting!