Nintendo Wi-Fi Help!

Help, guys!
I have a problem with my Wi-Fi for my DSi. I have the connection settings right, and the test was successful. I go to my Pokemon Platinum, and am trying to recieve Shaymin over the Mystery Gift via Wi-Fi, which is currently on. I tap "Recieive via Nintendo WFC' and it tries to connect but fails. I can access the DSi Store on my DSi with Wi-Fi. But I really want Shaymin, and when I try to connect on Pokemon Platinum. It fails. Please help me!

I think u can only get it on pearl or diamond then trade it to platinum

Try manually set your DNS address you can get shaymin directly on platinum i did with both my saves. Mine used to do the same thing for some reason mostly in pokemon mystery gift (sometimes crashed while trading), solved with the DNS.