[Tate]

When I was trying to create keyboard short-cuts I too couldn't make the majority of them work. However, after some trial and error, I did find a few.

The one I use now is apple/control/Z.

Although, intellectually speaking, I don't really like this since it has nothing to do with the "undo" function normally assigned to apple-z, physically speaking, I love it since it is close to the bottom of the keyboard and my middle finger falls directly on the "z" button when my index is on the apple and my pinky is on the control.

This makes it quick and easy like the default Quicksilver shortcut and I have been using it liberally!