This is because since 9.0 attwifi have not Nintendo Zone access flag enabled for attwifi SSID and WebBrowser is not enabled for NZ@McD1.
However I'd recommend set SSID to NZ@McD1, because now for attwifi you're only getting the same linus/router and native US attwifi nintndo hotspo users only. Win NZ@McD1 you can get spotpasses from mor eusers, because Windows users can reach them and because NIntendo are distributing spotpasses between several to all european hotspots. So there is not much csence using attwifi for now, unless you're trying to open all the US map in the MIi Plaza