Yeah, it doesn't sound like SPServices, as it ought to work the same in the two environment, all other things being equal. If you can connect to the WSDL pages via the browser, this it mist be something else about permissions, I think. Any possibility that someone has tried to be "smart" and lock down the Web Services? This would break many other things, of course. Another thing totry is connecting to the Web Services in SharePoint Designer as a DataSource. SharePoint Designer uses the Web Services to talk to the server, so that may give you more clues.
M.