Is the NFC Technology in the GN(GSM) different to newer Handsets like the HOX and GS3?

A NFC Payment option finally launched in my country(austria) this week.
So I did the natural thing, and registered my handset&exchanged my simcard, since I seem to need a specific "NFC-enabled" Sim to make this payment method work.

The thing is, it didn't. For some reason, and the people at the hotline didn't know why either, the GN and the Nexus S(as per their statement) are not "supported".

I tried it out at one of their promotion stands about a month ago, with various phones, amongst them the HTC OneX, XperiaS and a few other phones with nfc-stickers slapped onto them, and it would even work with the phone turned off(you don't need to confirm the purchase on the device, but you have a strict daily limit of 25€).

So I would like to just ask these questions:
Does the GN have a different NFC technology than "newer" handsets?
And - how exactly does Google Wallet work on devices in the US, do you need a specific Sim as well?(Which would be weird, since the premier Wallet phone is Sprint's NS, which doesn't have a Sim).