OK. I can ressurec Keldorn and he is still in my party but I cant make him do anything. I cant access his inventory; it just doesnt select him when I try to.

I had the same experience during my first run of the game.But it was Haer Dalis not Keldorn.Probably a bug or something.
What I did was to kill off the character or simply remove him and create a duplicate through CLUAConsole cheats.
Hope it works for you.(Smiles)

Just an idea- probably the bug answer is right but I would first try the priest spell aid to boost his morale= or take him to a temple, at least sleep. If not, then i'm sure it's a bug.