Install the .pkg and when it tells you to press restart DON\'T DO IT right away. Wait a minute because Leopard will recognize the card and ask you to go to network preferences. When that happens, press APPLY in network preferences.
Now you can reboot.
DON\'T TRY TO OPEN THE UTILITY TO WORK WITH THE WIRELESS CARD YET.
After reboot, go to disk manager and make a permissions repair action. After that, reboot again.
Now you can go to Applications folder and start the NetworkSelector app.