My DS Lite, purchased just this past March, has firmware v5. Someone [here] says he has wifi working on his v5 DS lite, although he bought it last year.
I know it's my DS because I can use wifi in homebrew on my fat DS with the same settings.
On that same page, someone mentions there's different wifi hardware in newer ds lites. He mentioned that the homebrew needs to be compiled with a newer wifilib. None of the homebrew I've tried (DSOrganize, NDSMail, Beup, DSaim) work with my DS Lite, so apparently they were all compiled with an old wifilib, but I am using the most recent beta of DSOrganize, shouldn't it be using the latest wifi library?