"The iPhone cannot be synced. The required disk cannot be found."

I recently ran across an iPhone that failed to sync in iTunes with this rather cryptic error message. It wouldn't allow me to sync any of the data quite properly and at one point even refused to allow me to delete music from the device. After a quick google search I came across this post on the Apple forums. Apparently this error can be caused by a number of different circumstances, but in my case it was in fact caused by a faulty USB port. The computer recognized the device and iTunes could even correctly identify the data on it, but that was as far as we could go. After plugging the USB cable into a different port everything worked as it should.