Different difference key composite node.

I did some composting using the difference key node in Blender 2.49, tried opening the project in Blender 2.58 and the difference key node was completely different (or incomplete) it doesn’t seem to be for composting anymore, it doesn’t seem to do much of anything. I’ll stick with 2.49 for now, but I’d like to be able to make a seamless transition to 2.5. Anyone know about why the difference key is different?

Figured it out image 2 is where you set the key color or key image, it only has a one tolerance slider. Its missing the per channel tolerance sliders, as well as the selection between rgb hsv yuv and ycc. Way less control but it work, its great if you have an image of the green screen before anyone stands in front of it. Using foresight makes this an upgrade.