haha, this is tooo funny!!
I had the same issue in Milan, IT with AVIS!
They said I needed my card to prove that it is me at the counter, they didn't care if I had a USA DL or Passport with my photo and name on it.
Some people are just crazy like that....probally never been on the internet...and think there is a small person in the computer giving them the information!!!
I feel your pain!