oh man... naavadi, where'd you come from? Kaskus? Indowebster?
fyi, these guys just spitting whatever they want to make their post leveled. You shouldn't believe anything they said without a proof(including ds infected with virus, and downgrading dsi firmware on the shop {which is seriously... you can't})

for your case, what MJaoune said is true. Except if you still using that GE Flashcart you ask earlier on the other thread. The Wi-Fi won't work.
I think you can try patching the rom with our Rom Tool which you can find here: http://www.ds-scene.net/?s=viewtopic&nid=11056
see if it's working or not. If it's not get new flashcart like what MJaoune said.