@vz2anj: I read those exact same instructions and had the same problem. But, I just got this working with my setup. Here's what happened:
1. Purchased a
Medialink - Wireless N USB Adapter - 802.11n - 150Mbps - 2.4ghz - Windows 2000 / XP / Vista 64-Bit /128-Bit Windows 7 Compatible from Amazon, and it came with a CD containing drivers.
2. Installed the 10.6 driver onto my iMac (running Snow Leopard).
3. Nothing happened. I uninstalled the driver.
4. Found updated drivers at
http://www.ralinktech.com/support.php?s=3, and downloaded and installed version V4.1.0.0.
5. After an auto restart, a Ralink icon appeared in the menubar. But still, nothing worked.
6. Read the Huwgely's post (post #5) in this thread, and decided to unplug the wireless adapter from the iMac, and replug it in.
7. Something happened! Wireless Utility appeared with a list of Access Points. And in my System Preferences --> Network, a new interface appeared as "801.11 n WLAN".
8. Turned Airport Off.
9. Selected a wireless access point in Wireless Utility, and entered the network password.
10. Voila! Working wireless N usb adapter with Ralink driver on my Mac.