DS1 bought one of these cheats cards for his DSi last week. I've been trying to install the software from the website (no disc). I'm following all the instructions but it keeps coming up with Code 52 no signature, so it won't finish the installation.
I've been trying this for ages and, to be completely honest, I am really really fed up with it. I've Googled and I've checked YouTube. Nothing's working.
The only solution I haven't tried is to restart my laptop and press F8 and then disable driver security or something. I'm not sure I really want to do this.
I've told DS1 it'll have to go back to the shop and get his money back. (An added difficulty is that he was with his Gran and she bought it by card with DS1 giving her the money).
Cue massive strop from DS1 because apparently I'm doing it all wrong and looking in the wrong places. 
Please please please does anyone know how to get this bastard thing working?