It's not exclusive to the GBA; a lot of old LAN netcode has extremely low latency tolerance. Just look at how Mario Kart Double Dash handles netplay versus how MKWii does: or the Xbox version of Halo 1 versus the original Halo 2. The games were made with the then-reasonable assumption that all networked clients (or slaves in the GBA's case, but the distinction is meaningless to the end user) would be wired, and either directly linked to the host/master or all linked to the same router.Sounds like the GBA needs to learn some MF patience.
There's nothing about the protocol itself that mandates this - it's all in the software. Software made for the Wireless Adapter has a much larger tolerance for latency, and even attempts to reconnect a few times if connection is lost for this very reason.
