Okay, cool, got it. It's midnight here, but I checked your saved game. It seems there's nothing wrong with Holvir(and with other guys and gals) on my computer. That is, their IWD NPC scripts isn't giving them any trouble.
However, when I played BG2 game, sometimes Anomen or Viconia or someone else kept stopping(not every two seconds, but, maybe, two times a minute?), and I had to remind them to keep moving. That was annoying, yes.
If that's the case, try changing path nodes in your Icewind.ini:
Path Search Nodes=32000
(under [Program Options])
I'm going to bed now; if you've still questions, I may try and answer tomorrow, but this is all I have.