Sorry I'm so dense this morning. Was it 6 vertical shots like this?: OOOOOO
If so did you choose from all the +/- exposures as you stitched those 6 together?
Sorry it has taken me a while to get back to you, I have been on a course for work and very good it was too (unusually).
Yes the verticals were shot like this with brackets 1, then 2 then 3 and so on.
1 2 3 4 5 6
      +/- 0 stitched to become image neutral
      - 1.5 stitched to become image dark
      + 1.5 stitched to become image light
but then each bracket was overlapped about a third with the previous bracket etc. Then I stitched each horizontal set of images, so I ended up with a neutral +/- 0 image, a darker -1.5 image and a lighter +1.5 image. I then loaded them into PS through load images as a stack script. Then I highlighted the three layers and ran it through the align layers process. I might also add I was saving after each of these operations, as CS3 and my old XP PC had a tendency to crash a lot when working with this size of image and just when you did not want it too.
I then manually blended the three resulting layers with a variety of masking techniques I have developed.
Hope this helps.