I know this is a newbie questions and I cannot believe I actually have to ask but...
I picked up BG DA2 last night and I started playing with the Necromancer in a coop game and the animate dead spell would only sometimes work. Do you need a friendly dead body or any dead creature will do to raise.
Most of the time it would start to raise and than disappear.
I don't think you even need a body, but I am not sure about that.
A friend of mine had a problem with switching between skills without using the "shift". If he switched skills and immediately pressed the button for the new skill, he would first use the previous skill once before using the new skill. Perhaps this is what happening.
If not, I am not sure and have not played necro enough to be able to tell.