I have everything setup on my laptop, the 3ds finds the hotspot but doesn't get any hits. Also it can't connect to the internet, but can find the nintendo zone. It was working when it was set up on my desktop.
I guess I should report that the mac 4Exxxxxxx becomes 2Exxxxxxxx. But I still get streetpass hits, or well SMT IV hits. I turned off mii plaza, don't really have a use for it. If it helps, I'm using Windows 7.
That's what happens to me aswell, when using the NZ World Macs. My MAC address reverts back to its original mac. This also occurs on personal macs, but some work and some don't. Not sure if the ones that don't work, they have it turned off or not.