My Pi comes with 2 usb outlets which I use for the keyboard and the mouse. But I now need to get the wireless up and running for which I plan to use one of the many usb cards I've accumulated over the years. This obviously requires an extra usb connection, so I hooked up a powered 4-port hub to one of the Pi's 2 outlets and the keyboard, mouse and wireless stick are all now connected off it. Problem is, neither the keyboard nor the mouse will work at all. I'm using a 2A supply to the hub, so power's not the issue here. I also tried substituting a different powered hub in case the first was faulty, but it makes no difference. If I run 'lsusb' the powered hub itself and the wireless card are listed, but nothing about the keyboard or mouse. However I swap things around, it seems the keyboard and mouse will not work unless they're connected directly to the Pi's own usb sockets. What's going on here? Any ideas?