they're not the only one unfortunately
I had hours of fun with an Italian site a few weeks back - they wanted my "Fiscal Number" as I was booking from Italy - and they also insisted on a US ZIP Code, even though the credit card was UK based
A nice lady on the phone fixed it in 5 minutes - I think she said they just put in any old rubbish into those fields..............
You wonder if they ever try the sites out with real people