When I attempted to install Adobe Photoshop CS5 on Thursday 22nd December 2010, the installer got to 11% and stuck. I downloaded the trial as suggested by Adobe, same result. Eventually a second support technician who I spoke to the next day was able to put her finger on the problem and resolved it.
I have been trying to create Photomerged images without success since then, so on 4th February I bit the bullet again and called Adobe technical support. Eventually there was that eureka moment when I was able to successfully create Photomerged panoramic images again. The technician was audibly very happy with a successful result, all down to a malfunctioning preferences file.
The original photographs in the two creations below were taken with the Nikkor 10.5mm lens, in the first image I used 14 Photomerged photographs and in the second 23.