Map unmapped menu items to key combinations in Visual Studio

How can I assign key combinations to unmapped menu items in VS2008?

I want to map view.PendingCheckins window, but when I go to Tools->Options->Environment->Keyboard , I can pick the action but not开发者_开发问答 assign any shortcut keys. I'm sure it is simple, what am I missing?

I did this with no issue.

Just click in the "Press shortcut keys" input box, press the shortcut you want to assign, (optionally choose the environment in which you want the shortcut active - defaults to Global), and press Assign.

I am the one missing something ?