Its kinda weird... I think its just on that case specifically.
I've set "Next Tab Page" and "Previous Tab Page" shortcuts to Alt+Right and Alt+Left respectively.
So, when I create a new Command Window and try to use these shortcuts, it doesn't work. But just when the windows is blank, with no text at all.
I think it's just for Alt+Left and Alt+Right, I've test another shortcut combination with Alt and works ok, really.
Hope I've made myself clear. Thanks.