'm stumped. Just picked up new iPhone 5. have 10.8.2 Mountain Lion with latest version of iTunes. Dropbox recognizes device but iTunes doesn't. Help

My iPhone 5, with its fancy new cable and whatnot, won't show up under iTunes. I don't understand why. All my devices are checkmarked to show under Finder Preferences, but the iPhone doesn't even show up under Finder. However, the popup from Dropbox asking if I want to import my iPhone 5's pictures pops up. Any ideas? Thanks.