I can use WPA and connect to the DsiWare to buy games but when I load up Pokemon Platinum to recieve a gift from Mystery Gift,I can't find the advanced setting to go online with WPA.Is it possible or am I missing something?
In the advanced settings, you'll see connection 1, 2, and 3 like on any other DS. Those are reserved for WEP encrypted access points. You need to use connections 4, 5, and 6 which are reserved for WPA encrypted access points.
I have not tried this myself as I have a DS lite, but this is what I got from google. Hope it works
Non-DSi enhanced/exclusive games cannot use the connection 4/5/6 to access WPA. Each individual game handles the TCP/IP connections within itself. The games would have to be updated, and that is never going to happen.