WiFi/NiFi with Linksys WL-167G USB

I am using a DS Lite with Supercard Lite and FlashMe.
I can get all homebrew wifi apps to work fine through my Linksys and the same with games. I just treat it as an access point by putting it into Soft AP mode.
The problem is I have to switch between network authentication methods for them.
So for homebrew I have to switch the setting to "Open" but this setting doesn't allow my games to access NiFi. I have to put the authentication to "Shared" for this to work. I don't have to change any other settings on my DS, just on my computer.
This seems strange because you would think Shared is just a more secure version of Open, so Open would allow anything in, or at least it would allow things that could previously connect when in Shared mode.

Any advice?

Thanks, Andy