My 4th gen iPod (40GB, monochrome) doesn't appear in iTunes on my Macbook Air using OS X 10.6 It syncs fine on Windows Vista with iTunes 9. The cable works as I use it al the time with my iPhone. My mac is fine, as it syncs with my iPhone, and another iPod (nano, 4th gen 8GB). I've tried everything that google has told me to do, and everything that I can find from Apple's iPod support website. I've done the 5Rs from Apple's support, I've re-installed iTunes 9, and reset the PRAM on my mac. All software is up to date too! In the USB Tree in System Profiler it shows up as an iPod, but it doesn't show as a disk in Finder nor Disk Utility. The only thing left to do is re-install OS X, which I really don't want to do as it's quite a time consuming task. Is there anything someone can suggest as I cant keep borrowing my friends laptop just to update my iPod, and he can't afford to keep 20GB of music on his laptop so that I can sync.