Sometimes when talking to NPCs, it can take as long as 5 to 10 minutes of waiting between dialogue clicks to get to the next option. And when I say sometimes, I mean about 50% of the time.
This makes buying, selling, or doing missions a real pain.
Great opportunity for beer and sandwich break, tho.
Don't know if it's related, but I have a similar problem buying and selling objects and spending skill points. Takes forever from when I click the action to when the action actually happens. Again, sometimes 5 or 10 minutes.