It's gotta be the antenna. Find some inconspicuous way to mark your antenna base and then take it to the dealer. If they tell you they replaced it, you'll know.
Some things take a while. My nano takes about 5 minutes, and my hard drive takes about 1.5 hours. If you turn the car off, it restarts. Maybe he's taking too many short trips.
You missed the "give it a few minutes to index" part. I've gotten an ipad, two ipods, an iphone, an android phone, an android tablet, two flash drives, and a hard drive to all work fine.
Okay, that was pretty funny. If I leave it in its holster when I drive, it stabs me in the side, so I just move it to the glovebox holster when I get in.