This may be a dumb question, but why are you putting the wireless card in the SME box if you plan to share the SME connection?
Seems to me for similar dollars, you'd get better performance by using a wireless router/hub whatever, use a wired connection to the SME box from the hub, and wireless for the mobile users. That is how I do home users who don't want to break walls to run cables, much faster for the wired machines, and more secure too.
Just a thought !
Mike M