I've been having a frustrating problem lately. I use a Kinesis Advantage contoured keyboard and I love it. My current computer is a 2006 Mac Pro. The problem is that randomly the keyboard will cease to be recognized by the Mac. I wondered if the aging Mac was developing flaky USB controllers.
If I reboot the Mac (which I can do, since the mouse still works) everything is fine.
But a keyboard that randomly stops working is not a pleasant thing.