Yes that could be possible.
Another reason could be, that the airbags (or the car) have to be recoded. I think I read something like this in a German Forum.
I also think that the airbag error and the seat belt error belong together.
Hmm ... thats a bit strange. Have you connected your seats to Terminal 30 or Terminal 30G?
Sorry, but I cant tell you the part number of the connectors. I used red mini-connectors from a local hardware store.
they looked like this one:
http://www.mindfactory.de/images/pro...0__7796001.jpg
they are for small diameters
greetings!