NIKON D70 QUESTION!!!

[AmFotog]

I'm at work right now and a friend of my dumped his camera off with me to magically solve the problems he is having with exposure, but i can't. On manual i took several shots to do an exposure test and on the lcd screen they look like they should, however when brought into photoshop on his computer they look underexposed and muddy. His screen is brand new and has been calibrated (when I loaded my own photos onto his computer they looked perfectly fine). If anyone can help me with this let me know asap! thanks in advance!

 

[tirediron]

How does the Photoshop histogram compare with the camera's histogram?