I used my "more expensive than the 360 usb" d-link gaming bridge and it worked beautifully. the 360 found it as a bridge and I just needed to put in my WPA pass and its worked great since. I will try one of my generic adapters with my second 360 and see what happens (although I did buy the 360 usb adapter).
On a side note, I am already in love with Live! Arcade. i am also happy to report no freezing issues on either of my 360s