I must say I was very disappointed with burial isle because of two major flaws.

1) Clerics can turn undead while invisable
2) The monsters keep repopulating

First offf I duked it out with a couple drowned dead and they pretty much kicked my high teen level party's butt. (Cool, I thought a foe worthy of a challenge) Next I turned undead, and they blew up, this was still challeging, trying to protect my cleric while he exploded them.

Then I discovered an invisable cleric could still explode them and NOT loose invisability. He was able to run (boots of speed) though the underground level turning and everything just exploded, he didn't lose a single hp.

I don't think he should be able to turn while invisable, turning involves the manifesting of his diety though holy symbols and the priests strength and presense, it would not work when invisable, besides it's lame.

Second it really pissed me off when I left and reentered and the dead where back, what a lame way to extend game play time. When I clear an area it should stay cleared, ok if it's spot where the dead just won't stay dead at least give it a day, not two seconds later.

Combine the instant repopulation and the invisable cleric it makes for extreme cheese, as an invisable cleric can reach level 30 in an hour of exiting, renter, making a big circle while turning, repeat.

I loved IWD, but BIS, these two flaws are very disappointing, and should be FIXED. I hope Gloomfrost is better.

What level was your cleric though?

I tried the burial isle with the maximum level cleric possible and the drowned dead just shrugged their plump evil shoulders and carried on coming straight at me.

Have you removed the xp cap if so you are probably playing the game with a party far more powerful than you are meant to therefore it won't be too challenging for you.

I agree about the turning undead thing turning should be considered an offensive attack like backstab or firing a bow so you should be visible.

As for the dead coming at you repeatedly I don't agree.My view is that if you disturb the dead once they'll carry on coming until you are dead or the thousands of undead buried on the site are, so its fair enough for them to keep appearing.

On a more general note I thought the burial isle was far too difficult as a starter dungeon a problem that manifests its way through the whole game. (its not a bad game just too hard at core level)