Calibrating 20inch Apple Cinema Display

Hey there,

I got my self two identical 20 inch Apple Cinema displays, one of them seems darker than the other though, I thought I go through built in calibration tool and would match them closely, turns out, that if I set gamma to 1.8 instead of default 2.2 it matches the other. When I finish the setup wizard and save my new calibrated profile, it saves it, but changes are reverted back to 2.2. What am I doing wrong?