undersexposed photos

I had several photos scanned into Photoshop 7.0.
After making a few adjustments I had them sent out for a print.
Without exception, they came back way underexposed. I was advise to have a gamma setting of 2.2. However, this is the default so it was already set. They then advised me to reset my monitor. I decided to download the photos to a CD. Then I uploaded them on another terminal and the photos looked great. Finally, I adjusted the photos to be much lighter using curves and sent the photos in again. This time to a different developer. Still way underexposed. Can someone help?

can you post a link to one of the worst examples - perhaps looking at the raw data may help.

If worst comes to the worst you could do your corrections by the numbers and not the data you see on screen.