When i plug my iphone into the dock, iTunes doesn't show my iPhone under devices. I tried plugging the cord right into the iphone, and that doesn't work either. However, the computer recognizes it when I plug it in...just not iTunes.
it happened to me a few times, try unplugging, or relaunch itunes, and restart computer, if still happens, drag itunes to the trash, and reinstall intunes, that did the trick for me