Assuming you shot the brackets from a tripod and the images are numbered
in sequence: If your normal exposure was the first in terms of file name
order add the images, on Source Images tab click "Sort", on Image
Parameters tab click "Link HDR...". If your normal exposure was in the
middle you must re-sort images manually after pressing "Sort" such that
the normal one is first of a set before you click "Link HDR...".
Another possibility is to create one pano from each step and merge the
results to HDR later (either in PTGui or in another program). To do so
load the images of one exposure into PTGui, load the project file (.pts)
from the finished pano as template via File->Apply Template->other,
don't optimize, create...
--
Erik Krause
http://www.erik-krause.de