I tried the HDR Merge Pro automatism. Used the ScottS template and reduced the detail and hit OK and what I got to see then was completely different fom the preview before.
My Photoshop is up-to-date and I tried another template and the result was different from the preview again.
OS: Win7 64bit HP
VGA: Radeon HD 4770
Software: Photoshop CS6 extended 64bit (from Production Premium)
Photo camera: Canon IXUS HS 125 - 8 megapixel photos
It was the color management. Normally Ps gives me a warning if the profile of the picture is different to my workspace profile but it has never done so with the pics from the Canon camera. It still doesn't and the checkmarks are all set.
I set the RGB from Off to Keep profile and now it looks like in the preview.