LinkVPit on 26 August 2012
Trying unplugging/reseting your router and see if that does anything. Haven't played any games online but my connection is fine for what I've used it for (downloading stuff, browsing the Internet a few times).
If you're having problems, it's more likely your connection is acting up or the online for the game you're playing isn't coded well rather than your 3DS itself is having the problem.
I can browse the e-shop, download stuff. Everything but play games it seems.