Changing keyboard shortcuts not working.

Ok, to keep it simply. I changed my desktop keys to make command + left arrow move me left a desktop and command + right to move my right a desktop. This works perfectly.

However, I put command + up arrow to move me to desktop 1, and command + down arrow to move me to desktop two. These two shortcuts work briefly, then just stop working.

I know the finder has command + up and down bound to something else, and I assume that it's these keys that are conflicting. How can I get rid of the finder key binds?

 

Ok, I'm sorry but I have no idea what that's meant to accomplish. :/ I did it, but I am not sure how it relates to the main issue I have, that my mission control shortcuts randomly don't work half the time.

Though creating my own definitely seems like a good idea, I have no idea what the "menu command" is for "Switch to Desktop 1".

http://imageshack.us/photo/my-images/27/screenshot20110722at122.png/

Basically "Switch to Desktop 1" and "Switch to Desktop 2" plain don't work. I want them to work.