I've been having a problem with a usb hub (no name hub) and my Intel iMac. Normally, all that I have plugged in to it is this: 1. 1GB Shuffle 2. 2GB Shuffle 3. 8GB 2G iPhone When I wake up my Mac, one or more of the devices will no longer be listed in iTunes. I thought that maybe it was my generic usb hub so I bought a Tripp-Lite. It's doing the same thing. I've been using the port that is closest to the outside of the Mac. Now, I'm going to move it in to the inside port. By the way, I'm using a brand new usb cable from the Mac to the Tripp-Lite hub. The other ports are used for a camera and for a printer. My keyboard and mouse are wireless. Any ideas?