I was unable to speak to him after a fresh installation. I verified the files twice, and now this works.

Now, I randomly cannot speak to the Inn Keeper!!! I spoke with him before. Now, it does nothing when I click on him!!

What the devil is going on with this game???

Try re-entering the building, or save-reload the game. I don't recall this bug in Icewind Dale, so perhaps this is some other issue.