Broadcom 4311 no wireless network found.

[freshfitz]

I took a broadcom wireless card out of my girlfriends compaq laptop and it worked in windows and osx86 on my dell d620. So I went and bought one on ebay installed it and it won't see the wireless networks on mac or in xp. So I tried it in my girlfriends laptop same thing no wireless networks found. So I bought a 2nd one on ebay different numbers but a broadcom 4311 chipset, same thing again whats up with these that they install but don't see wireless networks.