Mail custom keyboard shortcuts not working in SL?

[mcdj]

I like to change the keyboard shortcut for Mail's "Add Link" command from cmd-k to cmd-L via system preferences (done it plenty of times for other apps). Cmd-L seems to be reserved for showing deleted mail, so I changed that to something else and add my custom shortcut. When I try to use it though, it doesn't work. A check of the menus shows that none of my changes are present. Am I doing something wrong?