Maybe, maybe not. I have had many issues with my 3DS working right on wifi at home but whenever I take the same 3DS to my friends house it works just fine. Hard to say if there's a fix or not. :/ I hope there is.
As for the flags the OP probably proudly supports people like that, that's all. ^.^
Bad luck, I guess. With handhelds you pretty much have to sit very close to the routers or just have a good environment around. Some just don't like certain consoles and vice versa.
this happened to me the other day and i couldn't add people to my friends list/use online features.
either turn wireless off for a few minutes on your DS and then switch it back on and reconnect.
what worked for me though was restarting my router, even though my internet was working on my phone/laptop.