I have a tiger server that the usb mouse will not work. The usb keyboard works fine, but I've tried two different mice and neither will work. They light up and are obviously getting power, but nothing happens. Is there something that would have the mouse disabled? I can work fine in windows without a mouse, but I can't find any shortcuts to navigate through the menus to do what I need to do. Is there a shortcut to at least get to the apple menu?