i just beat iwd2...man, what a great game. i think its better than bg2. so im now in chapter 1 hof mode. i have just lvled up my sorcerer, and he now has wail of the banshees, but i cant seem to kill anyone with it. ive cast malison like 3 times on a group of enemies, but nothing happens when i cast wail of the banshees. if enemies have so many hps, does wail of the banshees not work?

Wail will work regardless of hit points, however it will not work on undead. Malison does not stack, so using it more than once is unhelpful. The only things I can think of that might explain your problem are:

1) You are targeting undead.
2) Your spell DC's are not high enough.
3) Your sorcerer is not close enough. Wail emanates from the caster so you have to be fairly close for it to work.
4) You just had a string of really bad luck.

Are any of these applicable?