First HDR - Gloucester Cathedral - Advice requested

The linked image is my very first attempt at an HDR image. I am not sure PS CS3 is the best tool for this, but I am curious as to what is going on with the light at the end of the hall? Some expert advice would be appreciated.

http://www.flickr.com/photos/saffron_blaze/8244481393/lightbox/

Thanks in advance...