I'm afraid I need a bit of your time because there's another unexpected issue going on here.
I wanted to customize the shortcuts, in the way Aharon Rabinowitz tells to do. It has never troubled me, until now. Although I doublecheck I saved the text file, and that I have all permission to do it, whenever I launch AE the file reverts to its original version.
Is there anything I do wrong? Does it just take the keyEd Up software to get it done?