If you've had a chat with Yurgir, and he's agreed to let you look for the last Sharran, you can run into this bug (which I've reported). (I'm not sure how many of these steps are necessary after this, except for one step for certain.)
Basically, go looking for the Sharran. When you find the magic circle with the book that describes a spell to break one person up into many, talk to the rat that appears.
Agree to not harm the rats in exchange for the location of the Sharran hoard.
Find the hoard, then go back to Yurgir's area. Just outside that, you'll find one of his merregons marching back and forth across the entrance to Yurgir's main area.
Here's the important bit: as soon as that merregon is facing the chasm, go into turn based mode and push him off the cliff, then leave turn-based mode.
Next, wander over to the displacer beast and examine it, roll the dice to learn about it, etc. If you then turn around and view the cliff that you previously left, you'll see the merregon that you threw off the cliff back where he was initially, except he's lying down on the ground next to the top of the cliff writhing.
At this point, if you start a fight (for example, by shooting a merregon that Yurgir can see), the fight is nerfed -- none of the enemies will ever attack on their turns until the cliffside merregon (the one who reappeared) is killed. They can do attacks of opportunity if you pass close to them, but nothing else.
You'd think it'd be a cakewalk at this point, but each enemy combatant (plus Flesh if you've summoned it) will take a full 20 seconds standing there doing nothing before the turn passes to the next in line -- plus there's interesting stuff that happens after Yurgir dies that you simply need to be out of the way of for a couple of turns. So, bring a book to read if you decide to cheese the fight this way (until this bug is patched) -- it took 35 minutes to get through it for me.
I'd be ashamed of myself for taking the "W" this way, but I was still very annoyed at having my (and very powerful) weapon permanently disappear when I was disarmed in one of the Gauntlet of Shar tests, so I figure I'm even.
I'll do it differently on the next playthrough...
