PC card nic question

PC card nic question for you.
setting up a laptop and now have 2 NIC's available
not that I matters for this one is a Netgear 411
the other is a Xircom (intel) cardbus nic/modem
both have been installed and ip addresses specified (10.0.0.85-86) for sharing a satellite modem via a proxy on the desktop, and work fine (one at a time)
The question being since only one can be physical attached at a time,( 32bit cardbus is a fat booger and takes up both slots) and the notebook recognises which is installed even after a hot swap, do I really need to bind them to different addresses? while both bindings always show, only the one for the currently installed nic is active (the bindings and other settings and privileges are otherwise identical.
Just curious :/