Installed new airport extreme card, must enter assistant to connect to a network

Hi. I'm using an oldish 17" macbook pro (a1261) running 10.6.8. A little over a year ago, my airport card started cutting off, with the only solution to be restarting the computer. I dealt with it for a while, tried using a USB network adapter which eventually broke, and finally decided to buy a new (used, warrantied) airport card. I had replaced a fan in it before and every so often I open it up to airdust it, so I'm familiar with its innards and the install went well. The one small problem is that to connect to a network, I HAVE to run the network assistant. It doesn't detect networks right off-the-bat or when "Looking for networks" from the icon in the menu bar. Furthermore, it seems to take a while for it to scan/detect even from the assistant.

My first thought: When I upgraded to Snow Leopard (which was actually pretty recently), It briefly ran an airport update. This was while my old, broken card was installed. Perhaps the new (used) card was last installed on a system which had not recieved that update and is causing some issues communicating with my system.

If that is the issue, is there maybe a way I can run some sort of update again? Or is there anything else that might be useful in calibrating the new card?

Thanks!