Can you tell us exact model of the air port module that you installed ?
Is the card listed under System Information -> Ethernet cards ?
Software Versions:
CoreWLAN: 2.1.2 (212.2)
CoreWLANKit: 1.0.3 (103.2)
Menu Extra: 7.1 (710.1)
configd plug-in: 7.2.1 (721.3)
System Profiler: 7.0 (700.3)
IO80211 Family: 4.2 (420.3)
WiFi Diagnostics: 1.0.2 (102)
AirPort Utility: 6.0 (600.92)
Interfaces:
en2:
Card Type: AirPort Extreme (0x14E4, 0x88)
Firmware Version: Broadcom BCM43xx 1.0 (5.10.131.36.15)
MAC Address: 00:1f:5b:b8:ec:21
Locale: FCC
Country Code: X0
Supported PHY Modes: 802.11 a/b/g/n
Supported Channels: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 36, 40, 44, 48, 52, 56, 60, 64, 149, 153, 157, 161, 165
Wake On Wireless: Supported
Status: Not Associated