My Apple keyboard does not work with OSX if plugged directly into my iMac (late 2013). However, if I plug it into a powered USB hub, then it works. Oddly, when I boot from Windows (Bootcamp), I can only use the keyboard plugged directly into the iMac. I don't know if this is a driver issue - it is a USB 3.0 hub. Can anybody help with what is going on?