I've searched a lot and maybe I found that in the future wireless drivers will "have to" disable the card when the interface is down:
ifconfig eth1 down will deactivate the wireless card. In some ipw2100 mailing list (don't have the link) this is discussed but it is not yet implemented -- Cannot turn off wireless https://launchpad.net/bugs/90883 -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
