Our article just came out in the June Shutterbug about using the Digital Calibration Target to achieve accurate color shooting digitally under controlled lighting conditions. The technique requires a full version of Photoshop because Elements doesn't have the Curves tool.
I immediately got an e-mail from someone who was having trouble with the technique when incorporating it into an action. We went back and forth a few times until I e-mailed him to call me and it took less than a minute to straighten out his technique.
It seems that he was actually opening the test image and creating the curve in the action, instead of creating the curve and saving it before creating the action. Photoshop doesn't have the most intuitive way to save and load custom curves because it hides it in the curves dialog. In fact, in the screen capture below, you can see that in CS3 it doesn't have any words, just symbols, to access the Save Curve or Load Curve option: