Yes I opened the image into Photoshop from ACR. The block artifacts weren't visible in ACR. The adjustments were mainly saturation but I also tried contrast as well but not clarity as I think it wouldn't be appropriate for a sky. As mentioned I have used Viveza 2 a lot and I was trying to mimic what I did with it in ACR to try and evaluate the effect between the two. Obviously with Viveza you can make a change and open the changes as a layer in PS. Go back and make changes and open as another layer. I am talking about the brush method and not the control points. In ACR I made a few changes and tried to undo them and redo them. Would that have been responsible? I am reading Jeff Schewe's book on version 6 so can I blame him?