Record 3D Movies On Your 3DS Starting Now

This is only half related but I have a genuine query: how do I download anything onto my 3DS without it cancelling half-way/never actually starting before cancelling?

I had this problem with the first system update thingy – it would either download perfectly, the progress bar getting to around half-way before the visualisation thing would slow and only show me getting 1 instead of 4 little information droplets (if you have a 3DS you know what i’m talking about) and make seemingly no progress before cancelling, or just start off with only 1 of 4 thingies then cancel after about a minute. After trying around 30 times to update, i googled the shell out of it and the only solution i could find was “format your 3ds and try again”, which I did, and it worked (but this seems to have been a one off thing maybe, the problem persists). I’ve since been trying to download the free Zelda game and now the update, but with the same lack of progress. I would format again, but over the last few months I’ve acquired all of those NES games (each taking about 20 tries before working), Links Awakening (same deal) and a million street pass hits and mii quest thingy progress and don’t want to format because I’ll lose all that.

Anyway, my router is fine, it’s super fast and stable for every other wifi device in the house, my internet speed and download capacity are fine, so why the devil do my 3DS downloads always cancel? Has anyone else ever had this problem/know of a solution other than formatting? I’ve tried being really close to the router, configuring wifi settings differently, downloading at 4 in the morning when the servers are empty, etc, to no avail. Is it my router? Is my 3DS defective? Am I just having bad luck? Does Nintendo Australia just have terrible servers? It’s infuriating I tells ya!!

Anyway, thanks very much in advance and sorry for the long rant/question. :)