I can go to Menu -> Scripts, but there's no MaterialMods there. Searching my mac I found a MaterialMods folder. There's no changeGamma script in it. I opened the materialModButtons.py in text editor, and it references changeGamma.py but it's nowhere on my mac. materialModButtons.py does refer to a writeMats.py that I do have which goes with button "Inventory", and a set_mats.py. This folder is not in the Scripts folder so it doesn't show up there. Maybe I have a bad install. PP2010 seems to work at any rate. Though I wonder what else I'm missing.