Quest can't be done with nUI enabled
 

In Mount Hyjal there is a quest called "Mental Training: Speaking the Truth to Power." This is a quest that makes you answer brain dead questions with buttons to click, a thumbs up for yes and a thumbs down for no. I remembered the quest from leveling a long time ago and I couldn't locate these buttons during the quest. I turned off nUI and the quest worked. Just letting you know. It's a pretty minor thing.

Thanks

Edit : I am using nUI 5.07.25 Plus

I had this problem as well. However i believe that the new version of nUI fixes the problem. nUI 5.07.26. Give that a try and see if it fixes the problem.

hmm strange, I have never had a problem with that unless they changed the quest mechanics since Cata. All of my toons did that near the beginning of Cata when they reached that stage in their questing and had no problems. That was probably version 5.07.24 or earlier that was running there. I assume its the same bar that appears when you throw the bears off of the tree in Hyjal. If so they are definitely working in the latest version as I did that daily yesterday.